What you appear to completely misunderstand is the importance of being able to handle the bike at slow speed 'before' going on the road and that some exercises generate wider skills other than simply your gripe of the U turn.
thats what I was thinking...
if U turns and the logic behind doing one is to difficult to grasp best you stay of a bike...
IMO one of the biggest steps to doing a U turn is confidence and always look where you want to go, and we all know to many riders wipe themselves out because at a critical time they are found wanting in these two areas.