in my personal opinion it seems that many atheists are bitter towards theists and the concept of god.
many people who convert from theism to atheism seem hostile and aggressive, but people who were never theists but dont believe in god seem calm and relaxed when talking about religious things.
this brings me to an opinionated conclusion that people who used to be theists and turned thier back on religion hold a grudge and are psycologicaly hurt inside.
I think you are quite correct. My take on it is that former theists are pissed off that their indoctronators lied to them and are simultaneously disappointed that their indoctronators dont have the faculties to understand they are lying or values to care that they are lying.