I agree with you--Victor is egotistical.
But he's also sophisticated with is ego...he has a purpose...a goal that it feeds. Let us remember that Dr. Doom is one of the most intelligent men of all (MU) time--in Reed Richards' range, mind you. He's met and communicated with every intelligent being out there--from the Phoenix, to Galactus, to every alien in between. Doom has literally seen it all. Therefore he knows better than
anyone that there is no scientific evidence that suggests that blacks are inferior to other human races. He knows that's not true--and to suggest he suddenly believes that stupidity is really an insult to
his intelligence.

It trivializes his greatness.
A
good writer knows how to make an antagonist's villainy potent
without resorting to cliched stereotypes.
Sadly, Mr. Hudlin is not--and probably will never be--that
good writer. It was blatantly obvious that he was "searching" for a way to get his readers to view Doom as T'Challa's enemy. Instead of creating some
sophisticated way of causing a conflict what does he do? Go for the lowest denominator: the race card (TRANSLATION:
"I really want my readers--who are mostly black--to hate Dr. Doom as my black protagonist's enemy, so I'll just make this classic villain insult most of my readers! Yeah! That'll get their goat! :rolleyes).
It's wack writing at its zenith.