I love the sort of multi nature of anime cons. The fact is, if anime cons were just about anime, I probably wouldn't go. It would bore me to death. I'm not actually much of an anime fan, but I like manga and games, and I enjoy seeing other aspects of Japanese life, as well as being a huge fan of costuming. When I think about my favourite panels and memories and such, not many of them have really been anime related. This year, I'm actually cosplaying my first ever completely non-Japanese character. However, I feel good about doing it because the film I'm cosplaying from has a reasonable following amongst anime fans, I love the character and I don't go to any other non-anime conventions to wear it. There are characters from other American comics I'd like to cosplay one day, but I'll probably wait until I go to a more general comic convention for that, as the characters I'd like to do are pretty much completely unknown amongst anime fans.
The thing about turf wars, I think if people are gonna put you down because you belong to a certain group, then these people are going to put you down whatever. They will find a reason, and what you're wearing just happens to be the most obvious thing because you stand out.
I see anime as the thing that links all the fans together, but we're all different people with diverse interests. However, having a taste for anime also gives us the taste to enjoy many other things the same too. Why shouldn't we celebrate that too?