Lexicus
Deity
I think their drive to proselytize is inextricably linked to their horrible politics.
I don't know if that's true. The drive to proselytize is going to be there if you see a difference between "is" and "ought," pretty much. Speaking as an apostate from New Atheism, I will say that the drive made (or seemed to make) a lot more sense in the milieu of the 2000s.
if atheists acutally lacked specific beliefs related to their atheism
"Beliefs related to their atheism" is not quite the same thing as arguing that atheism itself constitutes a belief system.