It's a combination of overinflated ego from intelligence (I am guilty of this 😏) and thin skin about having his convictions challenged. It's no different than the common liberal viewpoint

>I am fundamentally good, therefore you are fundamentally evil

>I am justified in doing anything to stop you because I am good and you are evil

If you think you know everything, and anything that is contrary to your position is "heretical", there is no room for discussion.