1. Good Characters Have Witty Lines.
Haruhi is flat and I'm not talking about just her chest size. She is rude, annoying, and apathetic to whatever the club does and somehow they find this endearing. If I was to do crazy stuff with my friends would I want to drag around a wet blanket to criticize everything I did? Just once i would like one of the main characters to snap at her "I know what I did was stupid, that's why I did it". Haruhi is not entertaining and she is not funny. My greatest fear is that other series will copy and paste this formula, populating the shoujo with shallow, overly sarcastic prudes that are somehow considered to be good role models.
2. Men are Entertainers, Women are Commentators.
The Host Club does a lot of crazy situations, however Haruhi barely does anything. Most of the time she just dragged into the comedy. I once mentally replaced her with a sandbag with a voice recorder taped on repeating the phrase "That is stupid." and it didn't change the format of the episode. There are only two points in the plot that she does anything noteworthy, when she helps the twins with a problem they should have resolved themselves and the grand finale which I will address later.
3.Parody Justifies Everything.
Seriously, half the dialogue in this show is fanservice for teenage girls. A parody is not playing every cliche straight than pointing it out. A parody makes fun of situations by subverting viewers expectations for the norm. Haruhi's entire existence revolves around reminding the audience that this is a parody with all the subtly of a sledgehammer. Making a stupid plot and then pointing out the plot is stupid does not make a good story . It just points out that the author's ideas are uncreative. They say this show is original but it couldn't be more mainstream.
4. Parody Incest is Fine.
Kaoru's and Hikaru's relationship is supposed to be a parody but how much is actually a joke? I mean they make incest comments all the time when their customers aren't around and Haruhi never buys their act in the first place. Girls are disgusted by shows like Koi no Kaze and Kissxsis but find this relationship to be endearing. Ugh!
5.Cliche Endings Need No Effort.
Out of nowhere, a new character, Eclair, is introduced and somehow is more shallow than Haruhi. Review continued in comments.