It looks like you've found something to fill the "religion shaped hole in your heart." Basically, people who get all excited and loud about their atheism are following the same template as the bible thumpers and cultists. They seem to feel the need to fit somewhere in a pecking order where there is an "us and them" mentality, then they set about making sure the whole world knows which side they're on, and how firmly planted there they are, not to mention how bad those who believe differently are. So, its not the belief system itself that brings them peace of mind and spirit, their satisfaction depends on waving said belief system around for the world to see and castigating those who don't subscribe fully to it.