Valve even said they raked in a ton of cash from micros for TF2. They said they made more in a few weeks with the game being free than they have total with the game in retail....
The difference is TF2 is a long-established game with a significant player base, Valve is a long-established developer with a positive community relationship, and Valve is reasonable enough to have mostly restricted rare items to cosmetics. They aren't (yet) issuing "season passes" for fucking products that aren't even IN STORES.
I love how every shitbag publishing head wants every game to be a service so developers can provide "an ongoing experience with fresh new content" for every which product, and then inevitably if a game breaks X sales it's "oh hey let's ship a sequel ASAP and abandoned last year's model".
Steam + PSN: PHJF