Probably because of how quickly Toriyama had to abandon Dr. Gero and 19 as main villains.
Still, those two are the biggest Goku haters ever.
If your last word is Goku's name, you really hate him.
I mean if you want to control all the saiyans yet you exclude only the one of them. You threat saiyans as disgusting barbarians but there is that one guy that disgusts you even much more. You could control his body and win but it's too disgusting, even more than sharing body with son of a man that killed your entire race.
Yeah, you totally hate him.
And Broly who doesn't even know other words than "Kakarotto" and gets furious everytime he sees something related to Goku, hears something related to Goku or just think about something related to Goku.
That is pure hatred.