maybe agatha christie and stephen king aren’t books that provide the grounds for discussion, but that doesn’t mean there aren’t books other than classics out there that aren’t worthy of discussion.
i would say to do your research and find books that you think would be just as beneficial. i think an interesting idea would be to maybe study and compare a contemporary book and a class as a sort of compromise. prove to your professor that there are books other than classics that can be learned from.
also, enlist the help of other students. maybe they’re not as passionate about reading as you are, but i can almost guarantee that they would prefer to read something more modern. the more there are of you the more noise you make. good luck!