Am I the only person who thinks that telling a teenager that their job is "to learn how to please yourself" may just possibly not be a good idea?

Granted, the mom clearly has huge issues that need to be addressed, and this kid needs support in her attempts to communicate. She seems to have her head on straight, getting very good grades and a variety of hobbies, but generally speaking, would you tell your average-to-above teenager that a C is fine despite their ability to do better because her job in life is to learn how to please herself?