Well sure, but I'm also rejecting certain things - for instance, I rejected all mathematics by virtue of choosing to study English. I also rejected studying the Classics by choosing a major where I wouldn't have to read them. I'm also not suggesting that it's possible to avoid all uncomfortable material, or that one should. But it's entirely possible to know oneself enough not to choose a course specifically on the horror genre, or to see a book on the syllabus you know is replete with, say, racial violence, that you think you might respond badly to and have a discussion with the professor about alternatives (if this is a class you must take to fulfill your major requirements, that is). I also think it's a little different to say "This topic is difficult, I'd rather not learn it" and "This particular lecture might give me panic attacks and make the rest of my classes today impossible to attend." I'm arguing in the case for the latter that there be a little leeway, that's all.

Additionally, I think something like English or History is a little different from engineering or mathematics, where disregarding a period or only briefly touching on it is not the same as skipping an entire topic like calculus, primarily because what now counts as "canon" and what a professor thinks is worth teaching is very subjective. Two different professors teaching the same period of English in an introductory level class at my university taught completely different works (e.g. my friends studied James Joyce in that class and I didn't; we studied play manuscripts and they didn't - in fact I don't think we had any overlapping authors at all). And the fact that I never read Middlemarch doesn't really change the substance of my education, I would argue, but that's pretty tangential.