Your point about the last 500 years - slavery, historical and contemporary ill-treatment of black people - must be a factor in this and therefore is also accepted.
Speaking of Charles Dickens, I myself come from a working class background - I'm the first from my dad's side of the family to go to uni. My mum's side are on the lowest rung of middle class at best and some went to uni. However, I don't hate posh people on sight or begrudge them their life-style - it's the hand they're dealt with, they're just people with all the good points and bad points as anyone else.
Also, how far back in history is too far? At some point a line has to be drawn, no? I'm an Englishman, does that mean I should carry resentment NOW towards modern Danes for what Danish vikings did to my Saxon ancestors?
I mentioned Joe Frazier (RIP) earlier in this thread and feel the need to mention his name again. He was Gullah, geechee, from a poor background in racist South Carolina. He had every excuse/reason to hate all white people on sight and feel sorry for himself. But he took advantage of the opportunity given him as an American and through sheer determination succeeded. IMO he should be held up as a model for all disadvantaged Americans - black and white.