I was musing on the resposibility for the extreme form of rollkur or the training method of choice for todays aspiring young dressage rider. I think the point I am trying to make is that, similar to any sport if you see someone doing something and getting results because of it, you want to copy it. So, we have a German showjumping rider who sees someone using a new stretching exercise on their horse in the warm-up. That someone then goes out and wins the class. "Aha, I need to use that exercise on my horses to get better results." the rider thinks to themselves and so they go away and perfect this new training method. This gets passed around and soon pretty much everyone is using the exercise and getting better results. The inventor of the exercise doesn't like this much and so looks at improving it. He asks the horse to bend more with it's neck, rounding it and tucking it's chin in. As a result his horse gets even better. This new method starts being copied by everyone and so the exercise evolves in rollkur (hyperflexion, round and deep). A German dressage trainer sees the showjumping riders using this exercise and notes how well their horses are going on the flat as a result of it. He goes away, studies the exercise in detail, the mechanics of it and how to ask the horse to do the exercise correctly. He then passes this onto his riders, who start using the showjumping exercise on their horses in training. Their results in the arena improve as a result.
You know what happens then. Another dressage rider sees this exercise and starts to copy it. Then their trainer thinks "If we ask the horse to stretch more in their neck, so that the chin is almost touching the chest, and keep the position for longer, then surely that will be even better for the horse." So that's what they do and thus the modern, extreme form of rollkur is born.
So is it the fault of the rider who originally came up with a new stretching exercise, or the trainer who developed it further?