College courses do not exist to provide an opportunity for student to "speak freely". They are not open forums for students to express themselves. Self-expression may be a part of a college course, but the school has absolute discretion to decide how much latitude is allowed. Treating the professor and the students as having comparable interests fundamentally misrepresents the basic nature of a college court.

"Protesting a t-shirt that pictured a professor who created a theory that states that students who get in on affirmative action are not as good of a match for the college, because they wouldn't have been admitted otherwise."

The professor says that the colleges are not good match for the students. You are subtly changing the focus of his theory to make it seem more offensive.

"At worst, it's a continuation of the idea that writing in a style of a non-white cultures is somehow worse or less professional."

That doesn't make sense. Writing styles don't have ethnicities, and pretending otherwise is leftist mind-killing. Different styles are more predominant among different ethnicities, but there is no such thing as a "white" writing style.

"To students who are affected by AA, that teacher was basically saying "you don't belong here." "

You are simply flaunting your ignorance. This took place at UCLA, which is part of the UC system, which does not have AA. Even if there were, the professor's writings was not directed towards UCLA students. The idea that no professor should express any thoughts as to who should be admitted, because those that the views do not benefit will take offense, is absurd. And again, you are phrasing it in the most offensive way possible. He isn't saying "You don't belong here". he's saying "You would have better expected outcomes if you went elsewhere".

I also wonder at your choice of the word "affected". Why such a obfuscatory term?