How else are you supposed to indicate that you're rephrasing something someone else said? It's generally pretty clear when something is an actual quote, and putting the quote in italics makes it very clear that it was not actually said.
For the teens, the psychologist's advice is literally: Well, maybe don't be such a bitch in the first place, Mom.
You can still use quotes if you really want to; you just have to write clearly that you aren't making a literal quotation --- to be clear that you're not putting words in someone else's mouth. But I find that it's rarely worth the effort to do so.