1. The notion that all good runners "burn out" has no basis in fact. A few might, sure. Most of the 'phenoms' reached their potential (and it wasn't world class). Lucky for them they have years of wins/medals/trophies etc to fondly remember. The 'would be but never were phenoms' who saved themselves..they got nothing. Its like saving yourself for marriage then getting hitched to an old sea-hag. There are no guarantees. Get it while the getting is good.
Bottom line..World class runners are few and far between, even from a pool of apparent "phenoms".
2. I coach youth track, go to national meets etc. I've never heard of this kid. Now, possibly I've just never heard of him and he has been running for 10 years. Not likely, but possible. His athlinks results are meager, fairly impressive but meager in terms of number of races.
In other words, he hardly seems overraced even if that were a factor.