They don't make the games you want (or I want, i.e., Half Life), but they clearly are still making games, and games they have made in the last decade are currently #1 and #2 in concurrent players:
I used to be a huge TF2 fan, I've got about 2k hours logged. But I haven't played in a long time, it really needs a breath of fresh air and to bring out TF3. I get that they are still making a killing off in game purchases, but they could do the same thing with a newer version, allowing people to bring items over with a 'vintage' like characterisation.
My main competitive game I play now is overwatch. They took a winning idea, and improved upon it with many more classes than TF2, and took elements from other genres (ie dota and 'ultimates')
http://store.steampowered.com/stats/
Also in the last decade: Portal 2, Left 4 Dead, Left 4 Dead 2.