I can't speak to the culture and cultural norms of whole segments of the population. What I can say is that UVA is rarefied among state schools. For one thing it doesn't feel like a state school. It's academically quite good, and socially it's very Southern, elite and loaded with exclusivity much as one finds at northern Ivy League schools, particularly Harvard, Yale and Princeton. The school has chapters of
KA Order, SAE, St. A's, and St. Elmo's, along with several secret societies, and an entrenched campus-wide socio-political hierarchy; and AFAIK, none of the Greek letter organizations and secret societies (at UVA; things may be different at other schools) admitted or considered admitting non-whites, and, frankly, they were very selective about the white folks they'll consider/admit. To put it another way, back then, UVA and Ole Miss weren't all that different culturally.
In my undergrad years, it wasn't as though everybody did some sort of racially reprehensible thing so overt and extreme as donning blackface (or a KKK robe), but neither was that so uncommon or so scorned that one can say one hadn't seen someone do it and ape/hype African-American stereotypes while dressed that way.
Red:
Props for trying to understand. That's more than many bother to do.
From my own observation, it was about one thing: having fun at the expense of Black folks. It seemed to me the nature of the so-called fun definitely spanned a range of intents -- from mimicking Black stereotypes to which the actor ascribed and getting laughs for doing so, to expressly deriding Blacks -- none of which were laudable or excusable because by that point in one's life, one is supposed to know better than to disrespect other people that way and by reference to vulgar stereotypes.