Leaving the switch-in to take the full brunt of the incoming attack, what's your point? U-turn isn't gamebreaking in any way, it is simply a superior option to switching that does a bit of damage and takes up a moveslot, whilst leaving the user potentially vulnerable to pseudo-status traits such as Flame Body, Poison Point and Static.Roserade is fragile. A silk scarf payback does 38.16% - 45.39% to max/max Rotom. What you don't seem to get is not that the scouting of U-turn is good, it is what makes it almost untouchable.
And another thing: from a momentum perspective, slower U-turn > faster U-turn. It was for this reason that I made my Crobat purposefully slower than other Crobats whilst briefly using one as a lead for one of my teams, and I never ended up regretting it.