Why do standardbreds wear flip flops, but farriers don't seem to use them on thoroughbreds?

Farriers don't use Flip Flops on Thoroughbreds due to safety reasons. Thoroughbreds are speed horses. Standardbreds are trotters. Flip Flops tend to make horses more aware of their feet which is not good for high speed racers. They are made differently, of a hard plastic with a cut to size shoe in the toe, these are for horses with bad feet, flat feet, low heels and weak walls and take a lot of shock.