It's not totally unreasonable for a company to unify login under one account. In the case of Facebook and Oculus, however, I don't think it makes sense from a customer perspective. In particular, I'm very concerned with the "black bag" treatment users get when they are banned from the platform. They are often unable to get any information on why they are banned, there is no appeal, and they lose access to hundreds or thousands of dollars of hardware and software they purchased. I don't think any customer would agree to such a setup if they had any choice, but they really don't: the contracts are not something a customer can negotiate, and the Quest/Quest2 are not products with any real competitor right now. Facebook and Oculus are not alone in this approach, and I think it's just as problematic elsewhere (Google comes to mind).

Facebook hit with antitrust probe for tying Oculus use to Facebook accounts - TechCrunch