Ultimately the upside of an open platform is that you can know with certainty that eventually literally any common need or deficiency it has will be addressed by the open market - if you are desperate enough you can pay and do it yourself. For example, when people didn't like Microsoft's desktop updates they created an entire alternative desktop shells. And there are now something like a dozen of these, some of which are / were commercial products. In an open platform, anything not addressed by the platform owner simply becomes a market opportunity for a third party developer. Of course, there are lots of downsides, but this is the upside.
But Apple's choice here to ship VisionOS as a fork of iOS and more importantly as a completely locked down system means that his ultimate conclusion is "maybe Apple will fix this" and alludes to hints of rumours they might do it. But this is what we are reduced to - disempowered, we simply hope that our overlords will have mercy on us, their interests coincidentally aligning with ours long enough that they do what we want. Or you buy into a competitor, but this just gives you a choice of tyrannies, not actual freedom.
None of this matters if you think Vision OS is a niche or a dead end. But if you actually buy into the idea that down the track this is the ultimate future of all computing, then it should be very concerning to be completely disempowered over it. I actually love the idea of a truly "spatially" aware operating system and I think eventually this is indeed where computing will go. So that is why I'm both excited by and very concerned about the direction Apple has taken.