As to obnoxious Homestuck fans --
I have encountered obnoxious HS fans before. There are going to be obnoxious people in any fandom, and in a large fandom like HS, there are going to be more, just because of the sheer number of fans. Those obnoxious people are going to stand out more than anyone else, just because they are more visible.
However, at this con, I ran into very, very few obnoxious or rude HS cosplayers. In fact, I was really, really happy because the vast majority of Homestucks I ran into were incredibly nice and polite. Homestucks, more than any other fandom I've been a part of, have a way of instantly accepting people. Some of the absolute nicest people I met at this con were Homestucks.
Here's an example. At the start of the gathering, I was really upset because my costume that I worked really hard on wasn't working out, I was late to the gathering, and I was in panic mode. I got to the gathering, and everyone understood perfectly and made me feel right at home. Someone who was cosplaying the same character I was took me aside and her dad fixed my horns so they would stay upright (which was the problem I was having), and they remained fairly stable for the rest of the gathering, though they were so large that I could hardly move. Without me even asking for help, perfect strangers were willing to step in and do almost anything for me because they knew that I had limited mobility. I was feeling much better at this point, because everyone helped me out so much and was so kind to me, even though I wasn't nearly as personable as I usually am because I started out being quite upset and then ended up feeling much better but in incredible pain and not being able to move my head much because of the amount of weight on it (27" horns, three 100cm wigs attached together, long ponytail clips, etc.) and because of the size and instability of my horns. Really, everyone there saved my entire day, maybe my entire con, from being a bad experience because they were all so, so good to me when I was having quite a bad day. I didn't personally witness anyone being rude or obnoxious at the gathering. It was huge, yes, but everyone there was FANTASTIC. (In comparison, I was at the Final Fantasy gathering the day before, and people were much, much less considerate -- stepping on my bag, not paying attention and walking into my costume, being rude, etc. There were plenty of great people there, too, but I didn't get nearly the same treatment by FF fans as I did by HS fans. I was in large and elaborate costumes for both gatherings.)
HS fans also seem to be the most likely to treat a cosplayer as a person in a costume, not as some pretty thing to be looked at/photographed/touched, which I'm thankful for. Again, in comparison to the FF gathering, I was treated like a person in an elaborate costume, not as just as elaborate costume.
As for HS cosplays being lazy, yes, some of them are pretty simple (my "lazy" cosplay, which consists of a knit dress, short wig, and boots, that I wear when I'm too tired to wear something else, is HS, and many of the costumes are simple shirts and pants), but a lot of other series have simple outfits, as well, there just aren't as many of them. I'd personally rather see someone dress up in a simple cosplay from something they like than not dress up at all because they don't have the right skills to make a costume. There are also a lot of really elaborate costumes that people do, whether canon or AU, and the people who want to do these outfits do these outfits. They are probably the same people who would be making an elaborate costume from something else if hey weren't into HS, but instead make a HS ballgown or an ancestor troll from giant horns and lots of detailing. My costume involved the aforementioned 27" horns, a 6+" double trident, a neoprene suit with applique work, and lots of jewelry. It isn't the most elaborate HS costume design out there, by far, but is anything but lazy. (My Sunday night costume was also HS and also not lazy -- it was a very fancy Rose cosplay, complete with blinged-out knitting needles)
I'm not going to touch the East vs. West debate, but I thought I'd put in some of my own personal experiences with how AMAZING the HS fandom can be, especially in comparison to other fandoms.