A couple thoughts going back to my College days. I had some professors who were respectful to disagreement and those who were dismissive. There is nothing worse than a professor who thinks they have nothing to learn from students generally. It sounds like you had a real issue with a really arrogant professor.
Secondly, I think you can take it as a supreme complement when such a professor dismisses conclusions because they don’t want to hear them. I remember a professor responding to a paper I wrote which argued that “white” was code for “assimilated and successful” so Iranians weren’t considered white but Greeks and Italians were. He called it “the Book of Mormon thesis.” I think you can hold your head high on this one.