Well, I suppose if nobody cared about it enough to ban it, a book wouldn't qualify as "literature."
During my school days I defined a "Classic" as something that kept coming back no matter how bad it was. Of course I had a bad attitude about pretty much
everything they made us read -- partly because I didn't like the idea of being told what to read when I was perfectly capable of choosing my own reading list, but I think it mostly had to do with their making ninth-graders read
Lord of the Flies -- ninth-graders are messed up enough without doing
that to them, at least,
I was.