How come barely no strippers will do ballbusting even if asked?

[Gregwill]

Theres only one that does it, she doesn't do it that hard either but shes alright. The one time she kneed me there a little, and squeezed a bit but it still wasn't as hard as I hit myself there.
I've had a few different strippers I told them I like this but they aren't rough or do anything.