Also, prestige/symbolic capital is a powerful motivator. It seems to me that in the US, wealth is a major contributor to prestige, so they're often not dissociated in professional attainment.
I'd vehemently dispute that chartacterization. I've never once in my life run in to anyone who felt that way, with the possible exception of some politicians and union heads.
Just get 'em to 18 (or earlier - a lot will drop out) and get 'em out the door. Someone else's problem now, probably the state penitentiary.
I think it's also an example of the Dunning-Kruger effect, in which parents think that just because they have kids, it makes them experts at education.
This is ultimately harmful because it makes parents feel superior to educators in their respective field.