The RLA was an adjustment to rules enacted a couple of centuries back to keep labor from shutting down the key national infrastructure.

The previous rules were rationalized by national security/national interest, but twisted to the benefit of management. The RLA was a slight improvement on a bad thing which has it roots in the 1800's, well before airplanes existed.

The only reason unions don't try to abolish or amend RLA as it applies to airlines is because it's a big can of worms that everyone is afraid to open. You never know what sort of BS rules the airline coalition lobbyists might be able to buy off of congress. It could easily end up worse than it is now.

Is that a good reason to live with it? I don't know. Do you feel lucky, son?