I think it all ties together anyway. As European warmbloods get hotter and less "amateur friendly," that leaves a space in the horse market for calmer, more forgiving dressage horses. Even I can remember when people in the Western states of the US weren't riding either one.
To speculate wildly, I think it has a lot to do with how people's expectations of what a dressage horse should be have changed, which has a lot to do with the success and dominance of the warmblood. And subsequently, for the popularity of the draft cross as a dressage horse, which looks a little bit more warmblood-ish than an Arab or Appy or what have you.
Why did the warmblood and its way of moving become the dominant dressage paradigm in North America? Why not the Iberian horses? There's a question.
Last edited by thesilverspear; 12-27-2011 at 04:49 PM.