Hmm,
Good question e ven if its you Moff.
How about this then?
Hockenhiem is a fast circuit. To get the best from the car you have to run it low (extra downforce). That means that the rear supension has to be stiff. I mean really stiff. I mean so stiff that it looks like a stiff thing in a bucket of stiff stuff? (You get the picture).
Ergo the tyres are providing the majority of suspension movement and they tend to bounce around. TC will probably find this a bit difficult to cope with.
Anyway, that's my theory.