Why are American writers so good at coming-of-age novels?

From The Guardian:

JD-Salingers-The-Catcher--001 I dearly love a good coming-of-age story. The genre's very existence implies that at some point In Real Life, all shy, scabby teenagers will grow into the boots of mature self-possession, developing skins thicker than silk pocket squares and generally drawing themselves up to their full heights. There's hope for me yet.

Lately, I've read several – some funny, some desperately sad, some both – of a very high standard. Repellently prodigious Simon Rich, already a writer for Saturday Night Live despite looking barely old enough to shave, recently produced a first novel, Elliot Allagash, the beginning of which made me laugh so much over breakfast that a mushroom fell off the end of my helplessly jigging fork into my coffee. The resultant scald didn't stop me wholeheartedly enjoying the adventures of Elliot, black-hearted adolescent puppet-master, and geeky narrator Seymour Herson, subject of his machinations. Wealthy beyond the dreams of Croesus' and Midas' love-child, Elliot offers to buy Seymour high-school popularity, basketball fame and the class presidency, and does so by labyrinthine and atrocious means, stomping on the deserving as he goes. It's not pure whimsy – Seymour eventually, and touchingly, wises up to the soul-corroding side-effects of Elliot's vendettas – rather, it's a fantastically ingenious and unique approach to the tale of a turning worm (empowered by a puff adder).

More here.