Donating large sums and dictating policy are two different things. And you are a bit of a dissimulator, aren't you? The lady was put on leave because she used the n-word while delivering a rant about how black students' graduation rates were not tied to a racist environment. This instructor had far more to say, as well, that is controversial. 
Taken in context, the word easily can be understood to be aggressive, demeaning, and insulting. 
Accountability has nothing to do with tenure; deans and others have ways to spur instructors if they're loafing. The critical question is independence. This war on tenure is nothing but another rabid right assault on progressive institutions, in this case, universities.