I for one think that if enough people complain, the airlines try to listen. They're competitive and sometimes it works. A classic example: In the late 90s or early 2000s, DL announced they would start charging for cocktails in the Crown Room. The furor that resulted caused them to eat crow and apologize.

There are other times.

By the way, I would clearly argue on AA that a recent example of customer revolt causing change was the Soy "Nut" debacle.