so, these are my main issues with SAO
Pacing - The first arc is riddled with timeskips, which undermines any sense of tension the plot might have had. And it would have been bad enough if it was skipping around between important plot points, but it's skipping between what amounts to side stories. They feel like filler and destroy any sense of forward plot progression. If nothing else, the second arc has the characters constantly moving toward their goal.
Kirito - This guy doesn't get any substantial character development until episode 23. And even then, he's not an interesting character to watch. What is he? He's kind of nice, and he's sort of awkward. Watching him try to carry this show is painful at times because he's too bland to be up to the task. As for being a "Gary Stu", yeah. He's a blatant self-insert that gets things dropped into his lap more or less because he's the main character; the reasons are either contrived, unconvincing, or nonexistent. He doesn't seem to really EARN any of his prowess. And I mean, watching an overpowered character can be fun. But they have to do interesting things with their overpowered-ness, and Kirito doesn't. It's like if Superman solved everything by throwing it into space.
"Harem" - I put the quotes around this because I disagree with the label. Most of these girls appear for like one episode, guys, come on. But the meaning behind the words doesn't really change. When people complain about the harem, they're really complaining about the show's treatment of women. The way every girl falls all over themselves for the cardboard cutout of a protagonist is kind of sad. "But he's a nice guy and he saves them," I've seen some people retort. Hate to break it to these people (like that awful Japanator article), but women are more complicated than that. You can do this for one girl, maybe even two, but all of them? Come on now. It's not convincing in the least, and it's honestly pretty pathetic.
Tone - The whole harem thing can work in the proper context. But SAO wants to be taken seriously. It doesn't want to be Berserk or Black Lagoon or anything, but it places itself firmly in the realm of something that comes across as realistic. If the show was sillier, a lot of the complaints I have here would slide. But the way the show presents itself forces me as a viewer to consider it as something serious, not as dumb entertainment. It's why the harem doesn't work, it's why the fanservice is jarring and comical, and it's why the second arc's villain is too over-the-top to seem anything but out-of-place.
"Depth" - It's almost funny, really. Some people tell me that I should treat this like dumb entertainment, but others will insist that this is a deep show. They'll tell me this is some examination of the human condition, some grand statement about mankind (looking at you, Kotaku). And that's bullshit. People do this all the time, they look for things to justify their own enjoyment because they aren't secure in simply saying "well, I liked it." Any supposed "depth" here is incidental. We see people adapting to life in the game because that's the way the author was able to tell these side stories. But let's for a moment entertain the idea that this was meant to be deep. After all, it touches on the topic of humans adapting on occasion. So what? What does it say? How does it say it in a unique or interesting way? Why is it saying it? These questions can't be answered, because SAO only scratches the surface. At best. And it doesn't get points for bringing up the topic. This isn't Faulkner just because Agil copes by running an item shop, boys and girls.
Deus ex machina - It's ok to have the cavalry come in at the opportune moment every once in a while. But this seems to be the only way SAO knows how to resolve things. Asuna running to save the paralyzed Kirito, whatever the hell happened in the first arc's finale, the raid on the World Tree, Kayaba helping Kirito out against Sugo, and probably some other instances I've left out. It works the first time, maybe even the second time, but when you do it this frequently in a 25 episode series it loses any impact and becomes exposed for the bullshit it is.
Tasteless Portrayal of "Rape" and "Incest" - The quotes are here because that's what I'm going to call them. I know it's not incest or rape on paper, but it's easier to write that than it is to say "the romantic feelings she has for her brother" or "sexual assault" every time. These are two heavy, taboo subjects. They need to be handled with care or they derail your entire storyline. They're not handled with care. The incest is obvious pandering, and it's distracting. Worse, they expect me to feel bad for Suguha. Sorry, writers, I don't relate to this. There's a big wall between me and getting emotional, and it's labeled INCEST, just like that, in all caps. The rape is even worse. It's completely incongruous with the tone of the show, and it's entirely unnecessary. You can replace it with anything. It's just another evil act for the villain to perform, and that trivializes rape in a way it should not be.
Villains - Kayaba forgot. Why did he want to build his big world of dreams? He forgot. The viewer is given no satisfactory reason for his actions, his GENOCIDE, beyond "well i wanted to build me a world." And then once he reappears to help out he's generally treated like a swell guy after all. Mentions of that genocide? Nope. Any ambivalence whatsoever? Nope. Then there's Sugo, who's introduced sniffing Asuna's hair. He's a cartoon character, plain and simple. He seems laughably out of place.
Characters - Remember Klein and Agil? Sure you do. Now, think about how often you see them throughout the show. Their total screentime is minimal at best, and they're probably some of the most recurring characters next to Asuna, Yui, and Suguha. We never get a chance to really know them, and that goes for almost everyone in the show, including its protagonist to an extent. Character development is sorely lacking on all fronts, and almost everyone is filed neatly into an existing archetype. That's a problem for a show that is generally character-driven, and it leads to laughable episodes like the third one, which tried to make us feel bad for the deaths of a party we knew for 10 minutes, at best. Who the hell is Silica? Who the hell is Lisbeth? Who the hell was Sachi? They use "hey, cute girls" as a crutch to get the viewer to care. Yui is probably the worst offender, as they shove her "cuteness" in your face until it becomes repulsive.
General Stupidity - I don't want to go back and make a list of all the little things that jumped out at me as silly or stupid, but suffice it to say there was a hell of a lot. The general premise behind Alfheim Online, which makes no sense from a game design standpoint, is one. The sheer melodrama in ALO despite the removed threat of death is another. As is how Kirito and Leafa do not recognize each other. And also the way the show assumes we're going to just buy personalities being uploaded online or AIs gaining sentience. And plot contrivances like the keycard.