In the context of their time. That doesn’t mean the blackface bit wasn’t offensive. But one can’t logically say, because I deem it offensive now means it was always so. Society has changed. Not necessarily for the better, but change is a constant.
Society has lost all tolerance. It is not okay that people are being vilified for things that were okay within context of their time and place. This is the scary concept of “future crime” that used to be Science Fiction. Besides that, what is wrong with “black face” portrayals of black people? What would’ve been racist is to portray black people as white people.