Cosplay is not Japanese culture

Recently my family and I went to our local Uwajimaya for the Spring Sakura Festival. It's one of the many Asian cultural events they have every year, with informational booths and Japanese carnival games and traditional food stands. A large stage is set up so local taiko groups and karate dojos can can show off thier students' skills. The Spring Sakura festival is relatively small, and only one day, but it is a place where local Japanese can catch up with each other, local Japanese businesses can target a certain demographic, and people interested in Japan and Japanese culture can taste Japanese food, see certain factions of Japanese culture (including the forementioned karate and taiko, there were flower arranging exhibitions and calligraphy and the like). One thing that was different this year was the seemingly massive amounts of American cosplayers who attended the festival.

Cosplay (コスプレ) isn't particularly new in Japan, but the hobby of dressing up as one's favorite manga character is an expected evil with the increasing rise of popularity in manga and anime in the US. English how-to books are being published and more and more anime fans are jumping on the large-eyed bandwagon.

As a fan of Japan and Japanese culture, anything that gets more Americans into learning about Japan and learning Japanese is an all-around good thing. All Japanophiles have their epiphanies when the world of Japan opens up to them, and they see something wonderful. One of the goals of Uwajimaya's Japan festivals is to introduce Americans to Japanese food and culture, and promote Japan as a whole.

But cos-play is not Japanese culture.

I felt the sight of Americans dressed up as obscure Japanese cartoon characters in the volume that was there took away from what the organizers were trying to do, and I know there were Japanese people there that felt the same way. I fear sounding elitist, but cosplay is a niche of a Japanese sub-culture that the general Japanese population isn't particularly proud of. Is it wrong to think too many cosplayers at a Japan festival can change the atmosphere in a negative way? The fact that there were no Japanese natives in anime costumes makes me wonder if the American attendees weren't overstepping the line of good taste a bit. To be fair, all attendees were in good spirits and behaved in a proper manner. The question is, is it appropriate to treat a Japan festival as a comic-book convention, or am I being overly sensitive?

I would love to hear your thoughts on the matter. Convince me I am wrong, or praise my incredible insight!