Most race trainers are satisfied with the status quo and evidently figure that embracing the cumulative foolishness of their craft is safer than independent thought. After forward motion is established, horses don't pull with the front, they push with the hinds. When it comes to running fast, a horse is strictly a rear wheel drive model. Damned if I know, probably because everybody else does and Daddydiditthataway, the biggest cripplers of horses in the business. Toe grabs in front shoes are also directly or indirectly responsible for chip fractures, saucer fractures, slab fractures, bows and blown suspensories.
Tradition dies hard.
If one chooses to ignore the fact that few of these horses ever had the dubious benefit of our shoeing methods before coming north, the incidence of bucked shins in aged South American horses is one of the Great, Unexplained Mysteries of the Twentieth Century. It's also true they also don't run in grabs over there. Fair for one, fair for all.