I have a feeling they got caught with their pants down by the competition.
The HTC/Valve VR unit got revealed completely out of the blue and by all reports it seems to be a superior product compared to the Oculus Rift right from the get-go.
For Oculus, who, on a small scale, have been tinkering and slowly iterating on their Oculus Rift for years now, it must really hurt to be suddenly upstaged like that. They had all the mindshare for a while, now they are losing it at a rapid pace.
I think they realize that they absolutely can't launch with an inferior product alongside Valve, because that'll ruin any chance of gathering a good piece of the untapped VR marketshare. They realize how crucial it is to have momentum from day one and not just launch something shoddy and pray that people will stick with the brand. Because people won't.
I'm glad Oculus is continuing to iterate and trying create the absolute best possible VR headset, I just hope they don't take too long or it'll be too little, too late.
Valve and the Steam name have so much marketing, development and mindshare weight to throw around in the gaming world that I could see it easily taking the crown on that fact alone.