It's incredible that Kaka makes 135 times the salary of some of his teammates. He makes more in 3 days than some players make in a year. Here's hoping min salaries reach 6 figures next CBA
It's a tricky thing from the MLSPU perspective. Players want more money, but a significant chunk of union membership is wary of
too large an increase in salaries because they know that such an increase will result in pricier foreign acquisitions that force them out of a job.
In theory, the limit on international players should provide some protection, but MLS teams are getting really good at stretching their international slots by obtaining green cards for foreign players.
The percentage of minutes in MLS going to Americans is already noticeably lower in 2017 than it was last year. The speedy green cards are a factor, but in large part this is because the owners have added "TAM" spending on top of the CBA-negotiated salary budget and TAM is
mostly going to $500k-$1m type imports. A bigger CBA-negotiated salary budget would only expedite the process of replacing existing MLSPU member starters with David Accam/Mauro Diaz/Carlos Carmona types.
In the last CBA negotiations, the MLSPU went all-in on loosening weird MLS rules on player movement and only made a small amount of headway (free agency for longtime league vets, basically). I'd view the CBA a disappointing effort on their part given that player movement was such a focus. They did not exert nearly as much effort on raising salaries, probably for reasons mentioned above.
Beyond the dynamics between internal MLSPU factions, one problem for the players is that they don't really have much leverage. MLS spending (and quality) has increased to the point where we aren't seeing middle-class MLS players move to Scandinavian leagues any more because MLS has grown to the point where they can make more money in a better quality league playing closer to home.
In fairness, MLS players are in a tough situation. The median American MLS player needs to get better in order to demonstrate to ownership that significant salary increases are necessary to retain domestic talent. But even an improved median MLS player won't give the MLSPU a hugely superior negotiating position because of barriers to entry to many European leagues such as work permits for non-EU players (UK), non-EU player limits (Spain, France, Italy), and high salary floors for non-EU players (Netherlands).
I always thought that history of MLS salaries would be different if the UK didn't have their work permit rules. Non-elite Americans are a better fit for English lower league clubs on a cultural+stylistic level than they would be in many other places in Europe. If WP system didn't completely stonewall the vast majority of American pros, I'd imagine Americans could have been littered across the Championship and League One (esp 5-10 years ago when MLS salaries were lower), much as Scottish players are.