I have some trouble seeing how the person you're responding to is being condescending, unless you're reading into that ellipsis pretty hard (which is possible! punctuation in text-based communication has become so loaded linguistically, in fascinating ways.) This person hasn't told OP that they can't feel the way they do, just that their experiences aren't universal or objective, and they weren't especially impolite about it (again, unless we're choosing to read a significant amount of tone into that ellipsis.)

That said, I agree with your initial statement. Of course subjectivity goes both ways; it's a functional impossibility to determine if a piece of media is objectively good or bad, because no media can be interpreted through a totally unbiased lens. OP's perspective is valid, just stated in a way that's probably gonna rankle people who enjoyed the book.