How Do You Choose What You Absolutely Will Not Finish(DNF)?

What makes you not finish (DNF) a book? It’s hard for me to do this. It has to be an extreme the author went to in order for me to DNF it. I mean if it’s dated, then certain terms can be ignored or forgiven, even if they bother me. If it’s something relatively new, then I might have a harder time looking past what was said.

Racist comments, sexist statements, things of that nature really grind my gears, but sometimes I look past them based on the setting of the book. I know that if a book...