I really thought I cleared that up. Abuse comes in when the definition of success becomes skewed towards trophies, rather than partnership with the horse. When beginner and intermediate riders only see that recognition comes with trophies, trophies is what they'll go after. If they saw that recognition comes with ethical training, the mindset would shift.
I did not say lower-level riders emulate bad practices they observe. I said that lower-level riders slip into bad practices because their definition of being a "winner" does not include good practices, but only being the fastest, the most high-stepping, etc. Applying ethical practices in keeping and training of horses has to become part of the definition of success in equestrian sports, so even people who are not intrinsically motivated to do right by the horse will be induced to apply them. But only people who are already successful by current standards can guide such a shift, because they're the ones who are being emulated, admired, and listened to.