Its called Market value. You get paid based on your past play and projection of future play.
Market value is defined by supply and demand.
Just because the market value of water in most regions of the world is low (because of the high supply) does not mean water has a very high actual value (as in being vital to all life).
So the fact that Mason (probably) won't get a big contract does not automatically mean he is a non-valuable asset (as in bad goalie).
Also, players should not get paid based on their past play.
Their past play is one aspect to the projection of their future play, but should not be paid for by a new contract.
Mason wants a long term deal; I can't see an NHL team offering that to him at age 29 coming off a mediocre year.
One mediocre year.
Except for last season - when coached by a coach completely overwhelmed with the duties of handling NHL goalies - he was stellar during his stint with the Flyers.
And this goes back to your point of players being paid for their past play.
It does not make a whole lot of sense to project Mason's future play based on last year, but rather on his last 5 years.
And when you do, the most logical conclusion is that Mason probably is still a pretty good goalie who struggled last year.
But just for the record, the statement you quoted me on was more directed towards your argument that Mason's value / caliber as a player will undoubtedly be perfectly defined by the contract he will sign next.
And that argument is still really stupid.