source?
It's just an observation from playing the game. If you play on a run of the mill server (Valve/Skial etc.) I think you'll find that about 10% of the players will have any cosmetics equipped (barring things like the Gibus or the Pyrovision). I think that that's a nice portrait for your average TF2 player. On premium non-traders, I think that a lot of players, myself and a lot of friends included, are tired of or just don't care about the economy. There isn't any real way to measure that though.
I'm also pretty positive that Valve hasn't made a concerted effort on limiting inflation. Not one that I've heard of at least.