You'd have to be pretty damn entitled to ask for your donation money back, Jesus Christ.
But, then again, the internet is currently riding high on an unprecedented wave of entitlement - so that sounds pretty par for the course (sadly).
It's important to make the distinction between a donation and an investment. Lobbing £10 at a project you find cool on Kickstarter in order to help bring it to life and get it off the ground does not make you a company shareholder. Without the initial Kickstarter backing it's highly unlikely that the Oculus Rift could have made the progress necessary to attract massive corporate investment.
Is it morally grey? Yes, yes it is. But is it a betrayal to the original donators? Eh, no. I don't think so. But since funding games through crowdsourcing is just a new phenomenon - this was a bridge that had to be crossed eventually.