Cosplaying is a great activity. I make costumes myself and friends, and we go to conventions/ren faire in them.
The Cosplay Community people are the ones who take it too far, or who cosplay characters that they don't have the physical build for. Some people can cosplay Rikku. Some people should never be in certain costumes.
The difference between American and Japanese/French/some EU cosplayers is that they cosplay what they think they look like, and put a lot of time and effort into their costumes. Cosplay isn't a fun recreation, It's an intense practice of design and craft. Their costumes are the result of countless hours of labor.
http://www.circles99.com/elements/al...34/272yuna.jpg
A lot of American cosplayers cosplay what they WANT to look like, and don't spend the time or effort to make their costumes completely. Their costumes are vague generalities to give the idea of a character. And it is done for themselves, instead of for the love of the game/anime/artist/design.
http://www.fansview.com/2006/animecentral/0506a0025.jpg
This isn't to say that there aren't good american cosplayers, because there are. However, that's the big difference.
Some people want to use themselves as a tapestry of art, and create the garments to show their tribute to the artist that is their creator, and to show it to the world. Others want to make a costum cuz it looks col.
Some people are cosplaying a character, Others are making an outfit for a convention.