Guess what? That is very old school and dog trainers don’t do that anymore unless they are not smart enough to figure how to motivate dogs.
You know that when a dog steps outside of its boundaries, there is negative reinforcement, whether it’s a sharp “NO”, a tug on the leash & training collar, or something else.
I am not saying that excessive whip use is acceptable. What I am trying to say is that non-horsey people automatically assume that the whip is abusive (and it can be, used incorrectly, as one could argue there are many examples of). You and I know that as a training tool, the whip is not abusive and is used as negative reinforcement to tell a horse what NOT to do.
A few smacks down the homestretch if a horse is distracted or goofing off is acceptable in that frame. However, the whipping down the stretch in the Derby last year and the Preakness this year were visually not pleasant. We don’t know if every strike hit the horse, or if they were fanning the whip. Jockeys have been quoted as saying some horses shut down when they’re hit with the whip, and others respond, so generally I leave it to their discretion. In general though, yes I support limits on whip use, because there is such a thing as excessive use, and because an everyday person does not understand the crop as a training aid.
Edit: I do think we should be following GB’s lead on this, as I think the rules and regulations on whip use are pretty clear.