I think a lot of people misunderstood the question here.
He did not ask IF the donut thing was bad for the tyres, but HOW MUCH it was. Actually I think it's a sensible question, which myself I have been wondering about before. I know spinning is bad for any tyres, but how much do actually normal road tyres wears of skidding / spinning?
That however does not mean I will go out and spin shit up, and to be honest, I canot even spin propperly in my Hunday Atos, but well...
I like to see myself as a sensible person (BEHIND THE WHEELS), but asking a question should not make me an idiot. If anything I award the creator of this topic for at least asking what harm it would do before he actually does it