Dude, the guy who invented the whole occulus sold it.
Its rather obvious that he did not think it would be that amazing.
Mr. Zuckerberg also sold a lot of facebook, so he probably dosent have high expectations for facebook either.
OR he wanted to focus on development of rift - rather than constantly deal with securing venture funding, investor relations, etc. Maybe he would rather focus less on that and more on finishing the product. Maybe he wanted to sell when the price was high.
Several people sell their companies to bigger fish. Especially when in total, occulus didn't even have $100M in total funding vs the 1.6B offered by FB.
As stated on Google+, I will never buy a Rift if they lock any app to it. Facebook privacy is a flat out joke. It was proven to me by Facebook itself that there is no exclusion of strangers being able to read what you share to "Friends Except Acquaintances." The Like I saw on such a post was seen by someone in my friends list. As benign as gifting Steam games in return is, knowing how much of a failure their so-called privacy is, I deleted my account in a heartbeat and never looked back.