>>47156448U-turn, Volt Switch, and Flip Turn could have 1 BP and they would still be spammed.
They problem isn't damage, it's the fact that it gives you switch advantage. If you and your opponent switch on the same turn normally, you would need to have predicted what Pokemon they had switched into. However, if one person has a Pokemon with U-turn, it doesn't matter what Pokemon they switched into as U-turn and moves like it allow you to switch after the Pokemon they sent out is revealed, and unless you missclick, you'll have the advantage. If both players have U-turn, the slower Pokemon have the switch advantage.
The only ways to punish U-turn are by staying in and predicting what Pokemon they'll send in, or chip damage from Rocky Helmet, Iron Barbs, Rough Skin, and Hazards.
Volt Switch and Flip Turn at least have Pokemon immune to them, but U-turn doesn't have that drawback.
