I go on about it too.
but have you read the book where it happened?
Hank was in the middle of a super villain rant about how the Avengers would love him and invite him back if he defeated, SAVED THEM from a giant supervillian robot he had invented to "all but nearly" destroy the Avengers, which is when Janet tries to explain to him that he's batshit and should take a chill pill... So he slaps her.
Janet Van Dyne is professionally beaten up for a living, by gods, monsters, robots, mutants and aliens.
I mean sure it's a betrayal, she trusted him not to be a crazy asshole, but Janet was slapped once by a crazy person in the middle of a pinky and the brain scheme to become leader of the Avengers and probably next the World, I don't think that really the audience is taking the big picture into account here.
A giant fucking killer robot sent out to kill.
It you want to talk about the Ultimate Universe?
Yup, that's your standard asshole laying into some one smaller than he is to feel powerful when he is clearly aware that he is not. Text book.
Which is why I cheered when Captain America stood on his face.