Developers must share some responsibility for this, but they can do only what Apple allows them to do, and the business model for something well understood and with potential universal appeal like a game can be far more lucrative than a guitar-tuning app.
She knows how hard it is to raise children in a culture where every time they're out of your sight, they're tuning into a multibillion-dollar music, computer game, Internet and film empire that promulgates messages frequently at odds with small-town American values.