I remember when TF2 updates used to focus on gameplay balance and depth. Items like the Kritzkrieg offered genuine gameplay choices, and efforts were made to change classes at a fundamental level to better the game (such as the Pyro's air blast).
I still love TF2 and play it on occasion, but nowhere near what I did from beta up until around the Spy/Sniper update. I keep wanting to play more, but it's like items are now just collections of stat values derived from throwing darts at a board of sticky notes with random buffs/nerfs. And with hats providing such a large revenue stream for them, there's not really a financial incentive to fix anything wrong with the gameplay when they can just throw more items out each update.
To be fair, some of the items seem to have glimpses of inspiration behind them, but they're almost always still unbalanced and mostly only suited for crazy pub fun, which isn't necessarily bad. Kind of like the FPS equivalent of Smash Bros. Brawl.
Err, but as for the trading...
Seems kind of nifty, but abusable. Does Valve still use that ridiculous drop system that rewards AFK'ing in an idle server? "We don't want to reward items through in-game performance since that can be farmed, but having a reward system that is even easier to farm without players even being required to press a single button is better", right?
What's to stop me from idling on my PC every night, accumulating a healthy number of items, and trading the hats to noobs for copies of my most-wanted games? (Besides a larger electricity bill.)