I think it has more to do with unrealistic scenarios in things that kids are being made to read these days, and have been made to read in the past, and how it influences their behavior.
People are people. People are FLAWED at best.
I grew up in a family full of strong people, men and women. Strength is determined by how you handle things, especially adversity, more than it is by some silly book on a reading list, and how a fictional character behaves.
The PROBLEM is portraying unrealistic behaviors to impressionable youngsters. If the schools really want to show good examples of strong humanity, they should be having them read about real people that have overcome problems, reached their goals in spite of those problems. THAT would be something that they could benefit from. No fairy tales, no uber bitches, no mega princes. Just real people who've achieved something.