My guess is money laundering, given that the product is pretty vapourware-y (as a game dev in a past life: Vircadia looks more like 'how a web dev thinks multiplayer games work' aka basically unusable in a serious title).
I think you fundamentally misunderstand the stack. Their main usage of the platform has to do with a E2E solution with avatars, audio, etc. all synced without issue. These features ship with the client and other private repositories wrapping the core.
However, for usage to HN users they would be (likely) more interested in the SDK, the core, the underlying system, and how it can fit their use cases.
If you want to understand a small part of the scale of this project, you are welcome to check out:
