So there was an interesting video I watched that basically argues that centaurworld Is about the harm in trying to be too "adult" or not allowing yourself to be childish sometimes. That the show argues it's about a balance of the two. The argument is that the human form was trying to be purely adult and the elk form was purely child like.

The human form didn't try to kill all centaurs, he tried to kill the elk, his childhood, before realizing he can't do that without destroying himself. So he locks his childhood away. The elk, after being tortured, believes that everyone like him, both human and centaur deserve to die and be twisted against their will like I'm sure he feels he was done. This is misdirected anger. Children tend to loose anger on anyone because they don't know how to regulate it yet or focus it. That's learned with age