I suppose if you're aggressive or combative in your atheism, if you're out to prove religious people wrong, you could find yourself unwelcome. Same could be with aggressive or strident homosexual-rights people, or with aggressive fundamentalist religious people.

I'm a religious person, a left-of-center Catholic. I think I'm a person of faith, but there's a certain foggy uncertainty to my faith that doesn't fit the stereotype of religion. I feel very comfortable with agnostics - but I have to say that I sometimes encounter atheists and fundamentalist Christians who seem to be out to prove that I'm an awful person because of my beliefs (or because of my fogginess). They seem to have no ability to question themselves or their beliefs (or lack of beliefs). Yeah, people like that make me uncomfortable. They want to pick a fight, and I don't like being drawn into fights. And I certainly don't want to fight about things that are sacred to me.

-Joe-