I know a person that says that you have to choose the books you read, as you choose your friends; carefully.
I don't agree... While I consider some books as my friends, I normally give most of them a try. I read those books that caught my attention, or in other words (or more poetically articulated), those books who speak to me.
We enter now to the biggest dilemma, what makes a book good? I wonder, for you o for me?
It depends on the particular taste of the reader, the moment in life, and even their mood at the moment of reading.
So, no, I don't think this person is right asking people only to choose the "good" books to read, but at the same time (being an individualist), I respect her opinion. She's the one that is missing the fun of reading all the wonderful books out there.
In case you wonder, you got it right, I am a promiscuous reader! :)