I think I know where the negativity comes from. When you’re a native English speaker, "great" literature is usually defined by your teachers. That is, people who have enough experience of reading to understand that these old books are the best of their time and still relevant today. But publishing has become easier over the years and there are many good books around these days, many more of them more relevant today than the "greats" of literature. A few of them even make it on to the syllabus, but teachers usually pick one at least old "great", because they’ve taught it a few times before and understand it well.
The important thing to understand is that "greatness" is bestowed on books by someone other than you. And people far prefer to read books they have chosen themselves. So, at school, we’re forced to read these "great" books at the expense of books we would choose ourselves. A fair few of my classmates would have chosen graphic novels over Lewis Grassic Gibbon ("Sunset Song" was on my exam reading list, I read "Catch 22" on my own and it is far better!). Hence the negativity. You’re forced to learn a particular take on a book because that will get you marks in the exam. You don’t have to agree with it.
Disclaimer: I’m in the UK and have a UK Education. Other countries may differ. I know most people developed a district dislike of books they had to study, even when they did study great stories.