Don’t show it to the public if you don’t want their opinion. Assuming meta knew this, it’s pretty insane that there are people defending the honour of their billion dollar corporate bff.
Even when it isn't a "prototype" and simply just doesn't have a consumer version, the public will be negative about it. Look at the Apple Vision Pro. That's a shipping product with a massive negative public opinion because it doesn't have a consumer version and no one understands if they are "Pro enough" to care to buy one. Look at Microsoft HoloLens. That was a shipping product with some large Enterprise and Government customer contracts. But the public perception of it was miserable, which is partly why Microsoft dumped a lot of their research in that area and lost of their brains in that area to Meta, so it's ironic and hilarious to see Meta making the same mistakes again that Microsoft already made with a variation/iteration of the same tech.
Was there a lot of engineering, novel problem solving, and even new invention? Yes.
Does that matter to customers if it comes together in a product that they don't feel is good enough? No.
For a site focused on tech and startups there is an awful lot of whiteknighting for companies who should know and do better.