He may have been promoting the breed so much simply because there are many people there who don't know much about them.
I love QHs. In general, they are very quick and easy learners and are usually willing to please. One of the things about them that is so prized is their ability to get to full sprinting speed in the length of 3 to 4 strides instead of having to build up to it. Then, after a sprint after a cow, their ability to come right back down to a calm walk on a loose rein is another thing that is so great about them.
The reason why many western riders use curb bits is because we ride with loose reins. The curb bit allows the horse to feel the cues without actually having to put pressure on their mouths like you would with a snaffle. Basically, the curb gets the same results with a much smaller hand movement.
Gorgeous pictures of the Lipizzaners, I got to see them a few years ago when they did a show here in Texas. It was very impressive.