and that’s the problem, people sometimes lack the nuance that’s essential to well rounded critical thought and engagement. as an hbo prestige television enjoyer, i love a morally gray or even deplorable character as long as the subject material treats the character with the “don’t condemn OR condone” mentality. the same goes for literature imo.
its also largely dependent on the context in which the work is being taught (not so much when it was made bc “it was a different time” usually ends up adding fodder to frustrating arguments). for example, junior year of high school i found it really odd that my white teacher decided to use of mice and men to chastise the use of the n word, to a class of mainly black students. very weird and also not the point of the book (but she got better after this and instilled a lot of good stuff in my brain).
again, not to link this to the arts as a whole, but i feel the separating the art from the artist narrative exacerbates this as well. nothing is wrong with enjoying work from a morally dubious person but i think separating their art from their morals is a weird way of engaging with work. another example: a musician i really loved who was found out to have very off putting (borderline illegal) behavior towards women but from time to time i will play a song for old times sake. however when i listen, oftentimes i realize, yes these ARE the lyrics of a man who does not take rejection well. the work exists in the contexts of the authors morals but you aren’t and don’t need to be waving a flag saying “I CONDONE EVERYTHING IN THIS WORK”.
all in all, a huge key to engaging with classic lit critically is being comfortable with (not sure comfortable is the best term. familiar, maybe?) with gray area and be ready to navigate accordingly.