Maybe so, yet he is one of the worst offenders when it comes to running young horses. Something you have made very clear that you don't like.
You're right, I don't like it. I wish they were starting them at three. But as a trainer... I'm not sure he's had a lot of impact on the stock that's sent to him by the owners, and I'm curious about the "they used to be stronger" aspect, and whether it's true.
Lots of breeds of animals, created by people in short-sighted breeding programs, have gone through periods of increased and decreased health and fitness... Quarter Horses with the little tiny feet that were so in vogue in recent years, or HYPP. German Shepherds with bad hips. When the breeders can catch these trends early and reverse the course, it makes it a lot easier to repair to the gene pool.
We won't back a horse until they're 3 years old or so. Depends upon the rate of maturity, but much younger than that, their joints haven't fully formed. There's more than enough to do with respect to training in the first three years, anyway. We follow the Monty Roberts / natural horsemanship line of thinking, and we've gottten great 'join-ups' from our little group of yearlings.
None of them are racers, though.