Carmack screwed the analysis quite thoroughly, and now its too late for them. One of two scenarios is in play here:
1) Facebook bought OR because they wanted to diversify their holdings to make themselves more resilient to changes in their core market. In this case, Facebook will likely leave OR mostly alone and except for adding some money to the pot, but when it becomes clear that OR can not or will not scale at the growth that Facebook wants/needs, then it will get the axe.
2) Facebook bought OR because of some overriding strategy that involves OR's technology. In this case, Facebook will not be allowing OR to keep going the way they have been going, which more than likely means very little if any emphasis on VR gaming, and instead is intended as a social platform for virtual interaction. In this scenario, the best that OR can manage will be to get some games developed and released, but to that end there will likely be no support from Facebook.
Carmack was correct when he stated that OR needed two things: first, they would need cash infusions at several points to be able to scale at the rate that flash-in-the-pan games require in order to meet their sales goals. Without that cash, developers would be reticent to make any games that truly took advantage of the platform because then they would be locked to it with no guarantee that OR could manufacture enough units to *not* severely limit sales of the game developers product. Facebook solves the cash problem, but only by reintroducing another reason for developers not to get involved: Facebook itself. Facebook has burned many developers before, and consequently developers are less likely to become involved with them than they would have been with any other company (possibly excepting Microsoft).
The second thing that OR needs is developer support, which, for the reasons described above, the Facebook deal makes far more difficult than it would have been if OR had been bought by almost any other company.
All things considered, OR might fare better having been bought by Facebook than going it alone, but that is by no means clear.