Maybe whitewashing is a bit inflammatory because as you say, it isn't always so. Wasn't the actor Yul Brynner part Roma? He played a gunslinger of the American West in Magnificent Seven. But I do think that Marvel hasn't really played up that side of him in a while and I think that could be something interesting to explore. In my own amateur character analysis, I think the reason why his ego had grown to such proportions is because while growing up as a minority I am sure he and his tribe were treated as though they were inferior to the rest of the Latverians. To combat this he proabably became resentful and distrusting of anyone who was not a Roma and wanted to prove himself their equal. Nay, their better! After all, he did tell that to Namor in that dinner scene.."We were born better"
No matter what country a Roma goes, they are always considered outsiders. His family probably never had a permanent "home address" spending part of their time in Hungary or other countries. This is one part of Unthinkable I liked anyway. Waid has him remembering how his family was always on the move.