[gumby]

They might have overbet on VR, but they remember acutely that they "lost mobile" which was basically an existential threat for them. Through major* effort they clawed their way back to the top on mobile. I guess Z thinks that VR is the next phase and that they aren't going to make the same mistake again. He's certainly been interested since buying Oculus.

Even if they don't sell a lot of headsets, they will probably have more experience than anyone else on what works and doesn't, and how that relates to the experiences they need to create. Of course this depends on VR actually mattering, which I doubt. Perhaps some of that will apply to AR, though when that goes mainstream is another big question.

* Normally the adjective "heroic" would be appropriate to describe the level of effort, but somehow I can't use that word when talking about a company, much less one like FB.