Wow, so much misinformation.
It's been three years because it came about as a group of guys on a forum all making their own hmds when one decided to run a kickstarter for his design;
http://www.mtbs3d.com/phpbb/viewtopic.php?f=120&t=14777You would never normally see a draft design concept for a commercial product. There would be a year or so of ramping up marketing by now if that.
The concept has been waiting for display technology to catch up, panels created for use in phones are not suitable for good VR. Certain panels are better than others but they all have issues. It's taken this long and an aquisition of Oculus by Facebook for big players (Samsung/HTC/Sony) to come on board and develop custom made panels for VR.
In the age of mobile technology people are used to Agile development and rapid release schedules. None of that applies to designing, manufactoring (building new facilities for a brand new type of hardware product!) and then figuring out how to distribute your hardware globally. I think they've done quite admirably to go from a guy (kid) in his garage three years ago to be on the cusp of the delivering a consumer product by a $290bn company.
This comment was edited on Nov 3, 2015, 10:00.