OP speaks the truth. I've been saying this for awhile now.
When I think of the kids I coach, the ones who end up "best" (ie: fastest) are the ones that come from a general athletic background. They play other sports along with running, and have a realistic calm attitude about the whole thing.
The high-mileage hyper-obsessed pure runners who have been training their entire lives are guaranteed to become resentful of the sport and burn out hard.
Tuohy will likely never run as fast as she did as a HS junior. I can see Sydney achieving great success in the NCAA.