Rental car compnies seem to be the stingiest category of travel service provider, with meager or non-existent loyalty programs and relatively modest promotions. But they still have a policy of no penalty whatsoever for people who reserve a car and never show up to rent it. I'm not complaining about that policy, mind you, but it seems to be logically inconsistent with their relative stinginess and especially in comparison with the corresponding penalties charged by hotels and change fees charged by airlines.

Does anyone have an idea why this is?