Why are atheists so obsessed with religion?

[Tonus]

If I was an atheist, religion would be the last thing I would talk about.

Why? If you went through a process of de-conversion from your present set of beliefs, are you confident that you would completely detach from it mentally and emotionally? Could it truly become "the last thing [you] would talk about?"

So why is religion so popular here? Is it because Atheism is fundamentally empty, and correspondingly has no topics to discuss within itself?

I think the "emptiness" of atheism is a small part of it. Since atheism is the lack of belief in god, there's not much to talk about in regards to it, and what topics there are will likely relate to religion in some way.

Dont say - "oh its because religion has such power over my life", because unless you like in Saudi Arabia or Iran, thats an absurd thing to say.

I may not believe in god or follow any religion, but most members of my family do. To them, it's a very important part of their lives. The same with friends and co-workers. That is aside from the influence that religion exerts over culture and politics that can affect me directly or indirectly. I don't know if that is described as "religion has power over my life" as much as "religion gets in the way from time to time."

It's kind of like asking why we are "obsessed" with religion, as opposed to wondering why some of us are interested in it, or as in my case, fascinated by it and the ways it causes people to think and behave. I spent a number of years altering the way I thought and acted as a direct result of my acceptance of religion and belief in god. Having overcome that, I find it very interesting to see the phenomenon from the other side.