To all their little weaknesses I open people's eyes; And little plans to snub the self-sufficient I devise; I love my fellow creatures— I do all the good I can— Yet ev'rybody says I'm such a disagreeable man! And I can't think why!
A person who believes, or pretends to believe that being bluntly negative in any evaluation of another person or object is for their own good, far better than using tact or encouragement. This can be a sincere thing, or a thin excuse for being a Jerkass.
For example, a parent who tells their kid that their attempts at art are abysmal and worthless, because they want the child to go into the family business, which (the parent thinks) will be better for them in the long run.
Or the coach who constantly insults and demeans their players in order to motivate them to do better.
Or the person who's just plain unpleasant to everyone because other people won't fix their flaws unless you point them out in detail, repeatedly.
If the compassionate critic's victim actually cares about their opinion and wants to earn their approval, this overlaps with "Well Done, Son" Guy. Drill Sergeant Nasty adopts this technique during the early part of training, though the competent ones will vary the routine once their troops improve. This is also a favorite tactic of the Evil Matriarch and the Stealth Mentor. If the Compassionate Critic is actually paid to give their opinions on a field of endeavor, this overlaps Straw Critic. When the critic really does mean well, this is a form of Cruel to Be Kind. It may also make them a Jerk with a Heart of Gold.
A related Internet Persona is the "concern troll", who assures the group a forum is based around that he has their best interests at heart, and "you feminists would get a lot more done if you weren't always nagging about wanting equal rights" or "by being fans of shows that haven't been commercially released in your area, you anime fans are destroying the anime importation industry."
In Reality TV, the compassionate critic will always offer unsolicited advice to the other contestants; act as a talebearer, keeping any minor disagreements stirred up to a high simmer; and, in shows where someone is voted out, will often spearhead at least one effort to vote out another player "for their own good".
Compare and contrast the Caustic Critic, who also accentuates the negative, but isn't as concerned with the "tough love" angle.
Compare/Contrast Constructive Criticism. If anyone else tries to criticize the critic's target, may lead to Hypocritical Heartwarming.
Ranma ½: Ranma Saotome. Raised by a maniacal martial artist father who believes psychotic abuse is the only way to teach martial arts, Ranma grows up being very insulting and critical of Akane, his unwilling fiancee who also happens to be a highly insecure Tsundere. He never seems to understand the connection between referring to her as clumsy and unskilled and her subsequent hitting him in the head with a mallet or her Megaton Punch.
Genma Saotome himself is one, in that his insults and jeers towards Ranma are often intended to make Ranma fight harder or train harder — essentially, he hopes that by making Ranma mad, Ranma will push himself harder just so he can rub it in Genma's face that Genma was wrong. It's probable that this is why Ranma recurrently tells Akane that she sucks at cooking and fighting; he's trying to make her get driven to improve the way Genma makes him want to improve by insulting him.
Naruto: Umino Iruka acts this way towards Naruto in the first chapter; he reveals this is because he recognizes himself in his student and wants Naruto to do better, so he's always pushed him. Of course, after the first chapter he's nice as can be, probably because he realized that Naruto didn't know why he acted like that and thought he was just a Jerk Ass .
In Chrono Crusade, Satella is this way towards Azmaria at first, since her own mother was this way towards her as a child. Chrono convinces her—with the help of a memory that her sister used to be much more encouraging—that this isn't the best way to help Azmaria improve.
Film - Animated
Anton Ego of Pixar's Ratatouille could be one of these. He is the most feared restaurant critic in Paris, who brutalizes any chef who, he feels, doesn't measure up. However, it is also implied that he has simply lost his feel for the joy of food in general.
He also ends up giving Remy's cooking a glowing review, even after learning a rat prepared it, showing that he really does appreciate great cooking that meets his high expectations. That he is a regular at Remy's new restaurant at the end shows that he's willing to stand by chefs that he believe to be great, even if said support means he's disgraced.
In Tangled, Mother Gothel poses as this. Perhaps she even believes it.
Soul Music: Susan Sto-Helit. She constantly points out how stupid other people are and can't understand why they don't just change.
Twilight: Edward Cullen is like this towards Bella, often calling her stupid, fragile, weird, etc. Either he's very devoted to keeping her alive and improving her or he's just an asshole.
Live Action TV
Simon Cowell on American Idol, when he drops his Mean Brit image.
Ian "Dicko" Dickson from Australian Idol pretty much all the time — although he was originally hired as "the nasty judge" he's not mean for the sake of being mean. In any case, the role of "nasty judge" has been taken over by Kyle Sandilands (who initially replaced Dicko, then was a judge alongside him when Dicko returned to the show).
While Craig Revel-Horwood is generally seen as "the mean judge" on Strictly Come Dancing, this frequently takes the form of being the only one to give genuine, if unnecessarily blunt, constructive criticism (opening his comments with "you did this wrong, you did that wrong, you did the other wrong..."), whereas the other judges will often give gushing and unqualified praise before voting you a mediocre score anyway.
Chef Gordon Ramsay on Hells Kitchen. Of course, he's better known for being a Mean Brit (and thus this is the angle they push in his shows), but the compassionate side comes through on Kitchen Nightmares when he interacts with people who listen to him and respect his input, as opposed to the standard egotistical Reality ShowJerkasses he deals with on Hells Kitchen.
Dr. John Becker of Becker fame goes between this as Jerkass in his personal life, but in his professional life, he's this fairly exclusively, yelling at his patients in order to get them to listen and straighten up.
Dr. Cox in Scrubs is an excellent example of this, though at the same time he seems to put so much effort into some of his insults (i.e. calling JD by a different girl's name every day), it's hard to believe he doesn't derive some sadistic pleasure from it.
Police Major "Bunny" Colvin from The Wire does a completely sincere and heartfelt version of this at one point with the hotheaded Segreant Carver who is under his command. Colvin goes into a speech comparing the increasingly harsh tactics used by the police to those of soldiers holding occupied territory, and expounds about how he feels young policemen, including Carver are so focused on the game of making the right number of arrests, seizures, etc. that they forget the point of being police; protecting the neighborhood under their care. Carver himself evidently finds it to be Constructive Criticism, because we see in the following seasons that he takes Colvin's advice to heart, completely changing his style of being a cop, and becoming much more effective at the job. A part of Colvin's speech:
You're a good man, sergeant. You got good instincts, and as far as I can tell, you're a decent supervisor. But from where I sit, you ain't shit when it comes to policing. Oh, don't take it personal, it ain't just you, it's all our young police. Whole generation of y'all. You think about it; you've been here over a year now, and you got nobody on the street looking out for you, nobody willing to talk to you. Isn't that right? This drug thing, this ain't police work. I mean, I can send any fool with a badge and a gun to a corner to jack a crew and grab vials. But policing? ... Before we took the wrong turn and started up with these war games, a cop walked a beat, and he learned that post. And if there were things that happened on that post, where there be a rape, a robbery, a shooting, he had people out there helping him, feeding him information. But every time I came to you, my DEU sergeant for information, to find out what's going on out on those streets... all that came back was some bullshit. You had your stats, your arrests, your seizures, but don't none of that amount to shit when it comes to protecting the neighborhood, now do it?
Maximillian Galactica from Phoenix Wright: Ace Attorney: Justice For All is this. He comes off as a prideful show-off, constantly rubbing his victory at the Magicians Grand Prix into the faces of the other performers at the circus he works at, seemingly putting himself on a pedastal above them. But what he really wants is for the other performers to become as big and famous as he is, not keep themselves at the lower level they're at.
Whateley Universe: Jobe Wilkins, at the Super Hero School Whateley Academy. He talks down to everyone, no matter how competent they may be. At the Whateley Weapons Fair (don't ask), most of his appearances are as he walks up to a student vendor and lambastes him or her for design flaws. Except for his last appearance at the Weapons Fair, where he demonstrates that he really knows what he's talking about.
The blogger John Solomon and his followers/commentors present themselves as this.
Zero Punctuation: Yahtzee Croshaw styles himself as this (in the vein of his inspiration, Charlie Brooker) when he takes the time to notice the endless accusations that he "just hates video games", retorting that he only rips on games because he sees "potential being squandered in mediocrity". Indeed, even with games he admittedly liked, he tends to focus more on the aspects he had a problem with, at least partly because that's what helps make his videos both entertaining and thought-provoking.
Doug Walker, the real one, not his characters. Even with Twilight: Breaking Dawn, a movie that broke him due to its ill-treatment of abortion, he still said you weren't an idiot if you liked it and he'd be genuinely interested to know why you did. (he later pushes the dare even further with his least favorite movie of all time, The Garbage Pail Kids Movie, given he never learned of anyone who liked it and is open to hear on the reasons for someone who does)
SF Debris mixes this with Caustic Critic in that even in a bad episode he will point out the positive parts and he will also tear into the bad parts of a good episode. He also points out (and it is in the title of his Star Trek reviews) that it is only his opinion and that you can think and believe anything you want as long as you think about it. In fact on of the few things he take offence to is when someone calls someone else an idiot for not sharing the same opinion.
Evil Editor writes a popular blog wherein he hilariously mocks query letters that Real Life writers send for his critique— but beneath the snark is tons of genuinely good advice on writing an effective query.
In Red String, Kenta really seems to think that belittling Kazuo will make him into the man he wants him to be.
Jay Sherman, eponymous character of The Critic, only panned every schlock movie he ever saw because he believed that if people continued to watch bad movies, Hollywood would continue to make bad movies.
In The Spectacular Spider-Man, Norman Osborn mercilessly critiques his son Harry in this way, dismissing all of his problems while criticizing his sucesses. ("Football? Not really your strong suit is it?") He even manages to critique Harry by praising his best friend Peter Parker, in a way that makes it clear that Harry is a failureby comparison. As a result, Harry has issues.
Every military drill instructor everywhere. They really do want you to succeed, no matter how it sounds.
It also essential that they figure out who just can't succeed. Failing to cut it in training is one thing. Failing to do so in the field can be dangerous to both the person in question and anyone else present.
Additionally, eliminating those who can't make it early is a mercy onto them, saves the taxpayers' money, and allows those with a shot more attention. This is true in any type of training with a decent wash-out rate, from military training to law school. Dropping a student who can't make it opens a seat up for another student and prevents a student from accumulating debt and wasting time.
Parents. Especially parents who are stricter and have high expectations for their children.