[gerwitz]

The professor clearly responded to your "tuition dollars" concern, so I'm going to ignore A). But B) is an interesting question that I will assume is sincere.

"White Lives Matter" is likely to be controversial for two reasons. First, it misses the point of the Black Lives Matter slogan, as the professor addressed quite well. Scan his response for "focus and exclusion" for detail, there. Second, "White Lives Matter" does not stand alone as a statement in today's cultural context. No one could wear such a shirt and claim it was anything other than a counterpoint to "Black Lives Matter". Thus, in 2016, that counter-slogan comes with a very strong implication of "black lives don't matter." Which brings us to your more extreme case.

Wearing a shirt that proclaimed "black lives don't matter" could be seen as a wry commentary on American culture, if worn by a black student already known by their peers to be an activist for civil rights. Even then, the face value of that statement means it should be verboten.

And that face value is, I'm confident, what you mean by your question. I certainly hope that any university would indeed expel a student (after a warning) who insisted on making the statement that the lives of other people do not matter. The social purpose of universities is to improve society by increasing the knowledge and awareness of its members. "Other people don't matter" is an interesting stance to take for a socratic dialog around solipsism, but as a personal statement is clearly opposed to the mission of any respectable education institution.

Your questioning itself strongly suggests that you (like many) sense an invisible "only" before "black lives matter." I'd like to encourage you to re-read the "focus and exclusion" portion of the professor's response.