There are reasons why sterotypes exist.
I'm not saying that we should treat individuals like stereotypes.
But if people have the idea that queers (and I don't mean just gays) like to get dressed in outrageous costumes and engage in lewd behaviour maybe it's because... a lot of them do.
It doesn't mean all of them do, or even that a majority do.
Stereotypes develop when people notice a pattern in individuals of a given group.
Think of any gay stereotype...the lisper, the beefcake, the flaming queen, the momma's boy--
They have no basis in reality?
How do you suppose gay people find each other? They have to detect identifiable traits in others, and these series of traits develop into stereotypes.
Asking people not to be their own stereotype is counter-productive.
Rather, it's the parade itself that's counter-productive, whether it lives up to any stereotype or not.
If I had no knowledge of homosexuality, and no opinion of it, and I saw a Pride Parade, I wouldn't oppose homosexuality from a moral standpoint, I'd oppose it because it's so freakish.
But the people in the parade don't care. As long as they thousands of well-wishers egging them on, they will feel re-affirmed in their choices.