Valve isn't looking to be in the hardware game in the long-term, with the exception of expediting new technology like they have done with HTC and the Vive for room-scale VR. They want as many room-scale capable devices on the market as possible because they are confident most of those games and such are going to be sold on Steam.

They are not locking down the tracking technology (although in the short-term, you still need HTC Vive base stations, but that's just for now) and the OpenVR standard can be implemented by anyone and there are already integrations not just for the Vive and Rift (with SteamVR), but also OSVR.