I agree with you on this, as a gay man too. But consider how many people out there (you know which ones I'm talking about) would insist to both you and I that both of us are supposedly "choosing" our sexual orientation. We each know their allegation is nonsense, but those are the biases from which their worldviews operate.

Therefore, while I believe that sexual orientation is probably inborn/innate within most people -- I don't rule out the possibility that some people can choose their sexual orientations. I'm just not one of them.

I view religion in a similar vein. Your atheism seems like common sense to you. Monotheists, polytheists, pantheists, and even agnostics often analyze their views of the universe through a similar lens.

So I don't dispute that religious belief could be a choice for some people. Perhaps even for many people. For me, it isn't. Plenty of other Pagans and Christians will tell you the same thing, regarding themselves. And, as an atheist, you're essentially saying the same thing about yourself.