I still don't understand why Facebook management has allowed Instagram and WhatsApp to exist where they pretend your account is a separate entity to Facebook an

I still don't understand why Facebook management has allowed Instagram and WhatsApp to exist where they pretend your account is a separate entity to Facebook and just makes do with having it linked via shadow profile. Yet with Oculus they're being so hard and forcing it into the FB infrastructure at the most critical point in it's lifespan. Most tech critics of it are all perfectly happy using Instagram, I just don't understand why Oculus accounts couldn't have just remained the same as that other than some executive being judged by some poorly thought out metrics and using this to meet them.