Customers prefer constant prices. Aside from the perceived unfairness, there are, again, transaction costs. Any time spent by customers trying to figure out how to get the lowest price is still a loss.

Airlines get away with it because airline seats are in limited supply, making it a seller's market. The buyers have to take whatever the airlines give them. There's certainly a fair degree of public outcry about it; the fact that there isn't more is because of a combination of people not understanding it, the fact that most people only buy airline tickets occasionally, and the fact that there's nothing the public can do about it.