Well they are at one of the most exclusive and privileged educational institutions in the world. Where else would Queen's English be used. I get that it is deliberate, I honestly don't understand the point of using deliberate vernacular in this context.
Those kids are a hell of a lot smarter than I am. I barely got into a shitty state college. No fancy private schools. Wouldn't they be better served using their superior intelligence? Or maybe they are and I'm just too thick to get it. I'm probably not the only one though.
I could easily scoff this off, but I'll give you a legit answer.
It's done on purpose because in many cases, one of the struggles minorities deal with in college is code-switching. Talking and acting differently around white audiences, around faculty, and then switching back only when you know you're in a space that'll allow it. And when you don't, you are seeing a certain way, ostracized. Many of my peers suffered both fates; wearing themselves out trying to talk and act in a way acceptable to the campus socially, or getting too much flack for not.
Forgoing all that in protest is in fact a statement that they want to be themselves while attending these universities.