"Gamergate happened because gamers hated women" "Animemes revolt happened because they hated trans people" "Christians want to kill queer people and want all women to be handmaidens"
Why do they keep making up these kind of lies? They always ignore what people actually say or what actually happened, and keep making up lies about people.
I generally agree with your second model, but I also think that most, if not all humans (regardless of political beliefs) have warped and twisted urges that they are willing to give in to, unless they are taught some combination of morality, empathy, and self-reflection needed to keep those urges in check.
This doesn't make them all psychopaths. In day to day life, they may be pleasant people. But it does mean that they may indulge those urges when given the opportunity and the lack of self-realization, especially when part of a mob.
When I saw the reaction to the girl getting kicked out of college for saying the n-word at 15 years old, I could not stop thinking about the stoning scene from Life of Brian and how well it captures that attitude: People slavering for the chance to throw a stone at the blasphemer (violator of sanctity). They don't really care who it is, they just know they have a chance to feed the dark urge to punish someone, while being able to tell themselves it is a righteous act.
Then again, I guess I don't have a very optimistic view of humanity.