I hear you with regards to r/atheism being valuable outlet for atheist teenagers in conservative areas. The problem is that if it's to be a safe place for teenagers, it has to be a safe place for all atheist teenagers. I am curious where all the anger comes from though. When I was sixteen, I had a pretty ugly fight with my mother in regards to my reading books on alternative religions. I was furious and hurt, but I don't think I was ever rabid and angry at religion; more angry at my parents. Maybe it's a displacement issue.
My parents weren't even part of it. My mom is a superstitious animist and my father is a devout atheist. If he weren't I'd probably be some grand dragon or other in the Masons by now; his dad is like a 17th degree something or other.