Some of it are my own frustrations from first or second hand experience. I'm just young enough that I was a teenager during the later years of the statistic (allthough I probably weighed against the trend except for the driving part). Yet I've had time to teach since I came of age, and talk to people.
Most of it though is just empathic (pathetic maybe?) outrage towards what I perceive-- no, feel is a steady devaluation of diversity in people, children in particular. Diversity of experience, of interest, of priorities and values. Diversity of stories.
The collective narrative we impose on children is that we're going to give them this great education, they're gonna have such great opportunities ('yuuge opportunities), and we're gonna make extra double sure that that it's the greatest education bestowed on any generation. We'll know it's the greatest education because we're going to test them relentlessly. And they will be grateful. They had better be grateful, and make something from this invaluable opportunity.
I'm exaggerating (and sprinkled a little Trump in there) to make it more obviously self-serving, because we are not helping them grow, were growing them. And we're weeding the meadow of anyone and anything that doesn't fit the mold. And I need to get off my soapbox, because I'm rambling.