“Ken wouldn’t do that to Barbie, it’s out of character!” Babes, that is the point.
Ken and his discovery of the patriarchy and the way it changes him is the exact same as what happens with adolescent boys. You have these guys who were so close to you, wether through friendship or family become people that they aren’t due to both peer pressure and the desire to hold power. Especially with the whole “podcast bro” thing he had going on in the Ken Dojo Casa House scene, Ken represents all the boys that lean into the patriarchy and change for the worst.
Ken was always so sweet, he was stupid and lovable and would do anything for Barbie. Then he got roped into toxic masculinity and all of a sudden he was cruel and pretentious. This is the same path that many of the guys I was friends with as a kid fell down. Barbie represents growing up as a woman and Ken represents growing up as a man.