You've never heard "pay your dues" in this type of reference before?

It's a reference to either saying that more junior pilots haven't been through enough to have a valid opinion, or whatever hardship they are going through shouldn't be fixed because it's "expected" or otherwise normal. At the regional level it was usually levied by senior pilots who either didn't want to change work rules that no longer affected them or wanted to give them up for pay with an explanation that you needed to "pay your dues" like they did (although with questioning you would usually find out for them it was for a month or two instead of years due to movement). It still happens occasionally at the mainline level, although not nearly as badly.

This is only a reference to "pay your dues" and not the rest of the post.