I don’t read that many bad books, I take no pleasure in them. People sometimes talk about how they are going to gorge on book-junk as though a bad novel is a messy burger and there is a special joy to be gained from swallowing it. Not me.
I like many kinds of fiction and there are great writers in any genre, but I would rather seek out the glittering best of any given type rather than read that which is merely mediocre or indeed plain awful. So I do some research, take advice from people whose taste I trust. Hence I read very few bad books.