Limiting the number of matches per month isn't an effective solution. It then becomes a requirement to be competitive to do those three matches a month or lose out on potential points.

A system that inherently scales (based on the factors of current standings (either points or rank)) is much smarter long term. If done properly it would eliminate the need to do seasons to deal with massive point inflation and prevent the quantity problem.

Right now the ranking system is more of a very simple experience system. Great if these were just levels, ineffective if you are trying to make a meaningful ranking system. There are very few competitive sports that don't have any form of ranking change if you lose a match you shouldn't have.