The question is more as stated in the poll:
Should customers be charged when their cars are in for warranty work?
I'm not fussed who picks up the tab, be it the dealer or BMW, makes no odds to me. What does matter is that when my car is in having a defect rectified is it "right" that I should have to pay for a loaner.
The other issue is there's a complete lack of consistency, sometimes you get a freebie other times not. Depending on when/how you talk to and which dealer you visit.