That was my thought as well. The parents are making the rational decision that they can't afford their kids to fail, so they take every measure to make sure they get to a good start. A good start in this case meaning getting admitted to Stanford. It might have something to do with low-qualification jobs disappearing, which in turn means you have to have a college degree to be self-sufficient.

Once upon a time, you could be on your own when you were as young as 12 (yes, I mean ancient times). Not too long ago you needed only high school education to get a good job, so you're staying with your parents until 16-18. Now you need college.