Some horses rely off that if the rider has a horse under control. You can't hurt a horse kicking him. It's almost like a cue for the horse to break out after the third barrel. An aggressive rider can really get a good run in on a horse, but a rider that isn't as aggressive, and odd as it sounds, will almost confuse a horse on what to do if they don't push him. But I'm not going to get into techincal barrel racing, I just thought, after reading the OPs ridiculous blog, that the whole reason this thread was even started made a little more sense.
~Started young horses in Bosca te Ador, unto the two rein the old Spanish spade, brought them along with two hands that were gentle. Some fine reining horses as ever were made~