These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anvilicious: Willis doesn't tend to be very subtle about his points.
Base Breaker: Ken has had some divide between fans. They either feel he's a bland non-presence in the comic, or a grounding Nice Guy to contrast everyone's eccentricities. His attraction to Malaya and blindness to her faults makes get's him even more flak. Though, him abandoning his crush and cute relationship with Lucy has redeemed him in the eyes of some fans.
Broken Base: Amber/Mike was this at the start. One third of the readers thought they work together, one third thought one of them is emotionally abusing the othernote And given Amber starting the relationship with blackmail and Mike...being Mike, this group is split as well or that they're just plain not right for each other, and one third thought Mike's just waiting for the right moment to give Amber maximum suffering. Sometime before Amber and Mike got engaged, though, the arguments began to slow down, and the subsequent pregnancy, marriage, and getting Put on a Bus has made the whole thing moot anyway.
Ethan's collecting habit. Many in-depth discussions (read: arguments) were had over whether Drew is right and it's a harmful addiction, or whether it's an innocent hobby and Drew is being unreasonable.
Fuckface the iguana, despite simply sitting around with one facial expression. (This is usually in contrast to Malaya, who is less popular.)
Arnold, one of Ken & Malaya's roommates, also gets a bit of this. His appearances in two strips — telling Malaya to get a job in the first and telling Ken to "stop barking up the bitch tree" in the second — were enough to make him far more popular than either of them.
Faz and Ninja Rick, because they're both absolutely hilarious.
Lucy is VERY quickly being embraced by the fans, both for her stance on superheroines and her chewing out of Malaya.
When Robin is elected to Congress, she insists on wearing her sombrero while in session. Fast forward to November 2010, and Frederica Wilson.
In April of 2006, a strip called Bingo was released, which was about Ethan showing a Internet argument-losing bingo featuring overused and ilogical internet arguments, and one of these arguments was "Claiming to represent the fandom as a whole". Then, five years later, in December 2, which strip was released? The False Equivalence strip. Whoops.
In an early strip Ethan discusses re-run syndrome, and wonders which of the cast would stick around. Robin states it will obviously be her, but the strip suggests Ninja Rick. Cut to 2014, and Ethan and Amber have left Shortpacked, while Ninja Rick has faded into the background. Guess Robin was right.
Internet Backdraft: Mike and Amber's relationship, between those who think that if he didn't really want it (whether because it's the relationship itself he wants or because he's setting her up for a fall) there's no way she'd be able to keep a hold on him or that he's such a bastard that he deserves whatever he gets, and those who see Amber as using blackmail to rape him and think that she crossed the Moral Event Horizon when she forced him to start dating her and keeps going further over it the longer she keeps it up. Later events have not helped.
Any strip dealing with real life behaviors, be they stupid toy arguments or social issues, will inevitably get a hostile reaction from people insisting that the situation described is either nonexistent or a non-issue and accusing Willis of somehow forcing his opinions on others.
Mike IS this trope. He's capable of planning and executing extremely convoluted plans for the sole reason of pissing someone off and despite that most of the cast considers him a friend, with Amber and Ethan even up to a point of becoming a subject of desire. In fact, the above example is the only time his plan ends up not having the effect he expected, and even then due to actually trying to achieve something he thinks is good for her.
"whoreswhoreswhores". So pervasive is this meme that as soon as the Miller-directed The Spirit teaser trailer came out, most of the comments on YouTube were along the lines of "whores". The teaser didn't feature any actual whorelike behavior, but the actual trailer did. By then everyone had used up all their ammo.
A meta one. Whenever something happens in the comics that the fans don't like, they will post "DAMN YOU WILLIS!" in response. Became pervasive enough that Willis' Twitter account is named "damnyouwillis".
The Scrappy: Malaya for some. Some find her grating and annoying and hate her constant bitching while contributing nothing. The fact that she was created as the result of a fan's bitching doesn't help matters.
It really says something when her pet iguana, Fuckface, is a vastly more popular character despite doing nothing but sitting around with the same facial expression.
Roz also had this, with many of her appearances (Especially when she interacts with Jacob) causing fans to leave many negative comments for her.
Drew became this for treating Ethan's toy collecting as something more than a harmless hobby.
Villain Decay: Though Mike was already showing a bit of a soft side in It's Walky!, his relationship with Amber sanded off more than a few of his rougher edges. He hasn't stopped being a jerk by any means, but his more manipulative, soul-crushing tendencies have largely disappeared. Not only was last big gambit was only to convince Amber he was too big of a dick for her to be romantically involved with so she could be happy without him, not only did he need to be drunk to do it because "normal" Mike loved her too much to give her up, but it didn't even work.
Faz even moreso. A few months after his first appearance, he gradually lost any semblance of power and has been so thoroughly defanged that he can no longer plausibly threaten anybody. He's just a Butt Monkey now.
The Woobie: Leslie, especially during the time before she and Robin got together and during their break-up.