...you're talking about the whole "You look so FABULOUS in X piece of clothing" kind of voice, aren't you?
Well, I've never heard anyone talk like that in real life, aside from this one retarded show called RuPaul's Dragqueens, a few movies, etc. Even then only a few people actually speak like that, or whatever it is you're talking about.
Frankly, I think the reason certain people in general, not just homosexuals, speak like that is some sort of attempt to sound either feminine, dramatic, or they're just acting slightly stupid, pretentious, and "snooty"
It's either the above, or perhaps it's just the way their voice is. Not really an issue, in my opinion.