I think it has a lot to do with owners. A lot of owners just have the horses for sport, and they don't know a thing about them. They want the horses running, not sitting in their stall costing money. If the owner wants a horse to run, then the trainer has to run him. Not to say that it's ALL the owner, but I would not blame it all on Zito.
I know/agree about owners.
I still think Zito and Lukas are hypocrites. I know Lukas has the most Derby starters ever. I bet Zito is second. If they think the breed is too fragile, why do they run. If they care about the horse, tell the owner no. They've each won multiple Triple Crown races, why run any more if the breed is too weak?
Both of those trainers would have run their horses 5/6 times this year, before running in the Derby. That's a lot of racing before May. Yet I can only think of three of their MANY TC starters that got hurt during the series (Grindstone, Union City, Charismatic).
Matz came into his first Derby with the freshest colt ever. First colt to win with a five week layoff. Only five races (matched a couple times.) His horse breaks down. Go figure.