Gaited mules are very popular with trail riders where I am at.
However, I really disliked that mule's ground manners. I don't know of anyone who would put up with him setting back like that. He obviously never learned to tie. But maybe I can't blame the mule. He was ridden pretty roughly and was gaping his mouth the whole time.
The "trainers" may have skill but they have "0" finesse.
That was one unhappy mule. Maybe a skilled trainer could fix him, but I wouldn't want him in my stable. He's over my head.