Cattle, the point I was (unsuccessfully by the looks of things) trying to make is that tipping is discretionary. I only tip when I feel the person has gone the extra mile for me, I can't imagine myself giving a tip to the taxi driver for driving me to the airport or to the hotel maid for changing the towels in my room. On the other hand, I will gladly reward extraordinary performance (like braking speed limits to get me to the airport on time for my flight ).
So the way I think of it is : you have to be there because of your employer, therefore you have to stay in a hotel. But you don't have to tip, do you?