This is all speculation, but I get the sense that Valve understands better than anyone that 1) the VR market is a long game, 2) there are a number of minimum requirements for a VR system which are not ready to be commercialized yet (120hz, 10+ million pixels, eye tracking, etc) so no one is going to “win” in this round, 3) the developer platform and general developer relations matters just as much as the hardware.
It’s not so much “build it and they will come” it’s “build it, and the market, and the developer community, and land them all at once and they will keep coming”.
Valve has the luxury of having absolutely no one to answer to for their cost structure, so they really don’t have to show any particular traction metrics, nor do they have to put on any annual developer conferences to impress their shareholders. They can just focus on goals that won’t bear fruit for 10 or 20 years and they’ll be totally fine.
Valve is the definition of skate to where the puck is going not where it currently is.