But, the training market (the clubs and schools who select the trainers) seem to prefer tricycles. Would that mean they have made their "best" selection for the role they have to fill?
Probably the schools decide by economics. Some prat digs a prop in the ground and it costs an engine and prop. So, they "think" a nosewheel will stop that?
Then once you get a couple of instructors who have never flown a tailwheel and they breed like rabbits. I think it's called progress