Sadly, if you have ever held a union job, you would come to understand they are there to protect the weaker workers who have seniority, so protecting an aging player who makes a ton of money falls right in line with its agenda. The Union's agenda is not to help out the young or stronger worker, they have to put their time in for them to be valued in the same way.
While on a fundamental level I agree with you, that more deserving players would get the money, no union ever has been in favor of strictly merit pay. It runs counter to why they see themselves to exist regardless of how non-senior members feel or how it might benefit them.
This really isn't accurate. I mean, I'm sure different Unions vary a great deal in how they operate, but I have had a union job and it didn't work as you say.
In fact, brand new employees were paid exactly the same as guys who'd been there 10+ years. Seniority gave workers first choice of routes, so they had that advantage as well as more PTO, but the pay was the same for everyone.
I also want to say that although I'm 100% pro-union, I've been witness to union reps gaining too much power, to the point the company decided it would be more profitable to shut down a huge paper mill, and put around 400 people out of jobs.
My point here is that I don't think it's a good idea to generalize too much and assume that all union situations are the same.