I sometimes abuse ampersands

YA fiction is, by definition, concerned with the question of identity, first & foremost. I'm all for it, as various identity policies are a huge narrative kink & academic interest of mine.

But why, oh why do identities so often boil down to the hero's ancestry? I've read a dozen too many books that go like this: the protag leads his/her crappy/happy/whathaveyou life, until the moment s/he learns that s/he'd been adopted/planted by aliens/whathaveyou, and - bam! - now everything must change, for, obviously, S/HE'S BEEN LIVING A LIE WAAAH ANGST ENSUES. S/he then spends several chapters to several volumes, depending on how lucky the reader is, trying to lead a life his/her biological parents (whom s/he'd never seen before) would presumably want for him, and the final "screw it all, I'm going back to my old self" is presented as a moment of crucial character growth, to which I say: author, grow up already. And get rid of the damn cliches.

Is it a Freudian fantasy of sorts? Or is it a very cliched & screwed way of portraying the individual's revolt against traditions? Or what?

Anyway, this is the one plot I could do without.