Worse, he's apparently a scholar on antislavery and professor of African American Studies, i.e. a demographic supposedly more cognizant of barriers minorities face and importance of their getting opportunities like admission to Harvard.
No one is stating that Harvard had an obligation to accept her. People are expressing their dissatisfaction with Harvard's actions. That's still allowed, right?
[As a side note: If all private individuals/institutions impose additional hardships on ex-cons, then it's highly hypocritical for any of those individuals/institutions to complain about the recidivism rates. You may as well just send them all away for life in prison for any crime and be done with it if your plan is to hamper their efforts to move on after prison.]
You don't get to have it both ways.