Disagree with your underlying assertion that students do not read nonfiction books. Your textbooks are nonfiction.
In terms of more "classic" nonfiction materials, j don't think it's a very important skill. Something like Anne Frank's diary or Night can definitely be powerful, but I don't think reading a secondary source on the American civil war has any more value for a student than a chapter in a textbook.
It used to be a standard thing that young people said to express disapproval.
"Ms Johnson said I can't make up the homework I missed because I forgot my bag yesterday."
"Sorry bro, that's gay."