It doesn't. It only protects those few pilots at the top and then only if they manage to keep their jobs. The problem is the big unions are now in bed with management (look at Delta) and they share a common goal of allowing a large supply of low cost outsourced pilot labor in order to protect themselves. The dream of regional pilots to one day be one of those few is the motivator that drives the propaganda.

It wasn't always like this but the system that was originally designed to protect pilots has been morphed over time into a system designed to keep wages artificially very low. The problem is the very few senior pilots have all bought into it because they think it worked for them.

The system is sophisticated and entrenched and the propaganda runs very deep. It's not difficult to understand if you just stand back a bit and look at the whole picture.