Pilots will not challenge management for a number of reasons.
They are too apathetic.
They are not particularly bright wrt how to be effective.
I say this because many moan. Few actually voice their concerns to management. Those that do are generally abandoned by their apathetic colleagues. Its too difficult and percieved risky. And it would be if not conducted correctly and without threat and table banging.
There are official channels to use that don't involve radical union type movements, which most pilots believe is the only way it could be done. Simply challenging unreasonable edicts of management through the company established processes for aggrieved employees would get serious attention. They are obliged to address them.
Letters, phonecalls and emails are a complete waste of time as the company can simply ignore them. After all these are not formal complaints - simply an employee's opinion, from the company's perspective, and can therefore be dismissed. Who's complaining? No one formally.
I guarantee that if 1% of the pilot pool took up formal grievance, on a legitimate issue, the company would moderate their stance.