I have a Rift, but I've never purchased any content from Facebook's marketplace. I use Steam, because that's where my gaming library lives. As long as the headset is tethered to a computer, Valve is going to capture the content distribution revenue. Facebook had to make a standalone device, because they never had a chance of monetizing anything other than the hardware itself on the desktop. I think this is a point that is often overlooked.

Given the Facebook's generally poor history of ecosystem stewardship, I don't see why any gaming enthusiast would even want them to be the arbiter of VR content distribution. Valve is far from perfect, but I'd much rather give my money to them than Facebook.