Acceptance is the issue here, not peoples' sex lives. By the "keep-it-to-yourself" logic, Taphan, people should also keep it secret that they're married, and avoid wearing their rings. It's a sadly common attitude, and indicative of homophobia itself. Flip that around and think of how you'd react to someone saying "I'm okay with straight people, as long as they keep it to themselves and act gay." Would you be offended? I'm not asking for an answer to the question; just think about it.
As long as homophobia runs rampant, many GBLTQs will take the out and proud approach to show that they aren't ever going away, and the rest of the world's just going to have to learn to deal with that.
Besides, the question Roled is posing is, does it effect the way we treat others when we suspect others of being something other than straight, no actual knowledge of their real lives required.
And Sarras, just treat the girls that hit on you the same way you'd treat the guys whose attention you don't desire - let 'em know you're possibly flattered, if that happens to be the case, but definitely not interested.