The anticompetitive part refers to social VR. Today we have multiple social VR apps (Rec Room, Altspace, Bigscreen and more). While Facebook aims to be a big player in social VR they're not there yet; their Facebook Horizons app is still in closed beta.
Requiring a Facebook login to use the Quest puts the competition at an immediate disadvantage, as they'll have to use their own login or submit to Facebook login as well, often at the cost of cross-platform compatibility. Onboarding friction will always be less with the app where you already have an account.
That was a super interesting read (and view), thank you. I've been in Linux land for almost two decades, but I've also spent a week (or so) porting our Linux-based development environment over to Windows with the help of WSL. This sheds some light on how it actually works. Maybe I'll have to look over it once more armed with this new information and see if I can squash some of those remaining problems with our solution.
Requiring a Facebook login to use the Quest puts the competition at an immediate disadvantage, as they'll have to use their own login or submit to Facebook login as well, often at the cost of cross-platform compatibility. Onboarding friction will always be less with the app where you already have an account.
Facebook told Bigscreen developers to join Facebook or "be crushed": https://twitter.com/DShankar/status/1295825809496629248