A consumer product like the Rift is an entirely different proposition with an entirely different set of challenges. The Open Compute project was essentially Facebook giving away some of their data center designs and specifications (mostly things like server racks and power management), with a few other companies joining the initiative but with none of the designs actually being used on a significant scale.

Also worth noting, the head of OCP left Facebook today. http://www.pcworld.com/article/2111680/open-compute-project-...