Valve buys up dev teams that are about to shake the industry up. Valve haven’t actually been the ones to make something new in a long time. TFC, CS, Portal, DoD, L4D, Alien Swarm, Dota 2… were all made by outside dev teams that Valve absorbed and put their name on.

I mean, that's the entire point they have at valve. They want to get the people with talent recognition and resources. That's why they did all that stuff with the tf2 asset store. Fuck it, the community is better than us than making maps. let's get them to make maps, sell a thing that puts money to the map maker's hands.

Oh, these kids are awesome, they would do wonders with more money and an audience. Fuck it, here you go. Oh BTW, old man murray was an awesome site, let's get the writers behind that a steady paycheque and have them write the story for these kids and their wacky princess portal wall thing.

What's that, they want to use our cornerstone IP universe? Eh, fuck it, why not.

We can't make shitloads of games, let's just make it so that when people want to sell games, we can host the games. Fuck it, we just cornered the PC gaming distrobution scene.

Microsoft might fuck people over with their OSes? Fuck it, let's extend and contribute to linux in a symbiotic way, then people don't have to rely on MS to game on PC.

etc, etc.

valve isn't about making games, it's about extending the pc gaming ecosystem and making it so that people with talent get money, and people who want to play games can play them, and to bridge the gap between the two.