The way I see it, there are 2 sides to this -
1) The dealer is under no obligation to provide a loaner. If your TV quits working, there is little chance the stereo shop will give you a 'loaner' while yours is being fixed. Same goes for your household appliances.
2) In our modern society, we really depend on our vehicles...and I mean REALLY depend on them. Often, the failure of a vehicle can have a huge fallout both work and family related. IMO, the dealers need to better understand how even a 2 hour repair session can impact some people, and be prepared to offer a 'workable' solution.
Some dealers seem to get this better than others....unfortunately, this is the only area I could see my dealer improving on, as I 'depend' on my vehicle for business, so unscheduled repairs can be a little more than inconvenient.