It has little to do with race, actually.
Leftists have their heroes, idols and gods (lowercase g) and when they are mocked they react very badly.
A fraternity exercising creativity, bad judgment or harmless pranks was once rightfully viewed as complementary to the college experience, even when poor taste was involved. These are 18-22 year old males who are still being socialized and choose to do so in their own way. Patient administrators knew that this was, indeed, ‘just a phase’ and that most of the fraternity members would become productive citizens, proud alumni and represent the institution well.
But universities are now gossamer-thin bubbles of groupthink, easily pricked and therefore paranoid about any sharp objects such as legitimate dissent and still-legitimate high jinks.
I think its perfect that the ones with the zero-tolerance policies against free thinking are the free thinkers of the baby boom era.
Nice alliteration!