Earlier quoted context omitted.
IMO, you're thinking about this backwards. It's good that public school exposes children to many subjects - hopefully most of them. So that they can discover if they click with one of them. The real danger is that someone never gets exposed to a subject at all. College is the place to specialize in a subject.
But if their overall SAT scores aren't good enough to get into the elite colleges, won't we just be denying the eccentric geniuses?
For college and life in general, I think main skill needed is emotional regulation. Everything else flows from that.