When they didn't mention gaming at all, I had a feeling that something about the device made it unsuitable for it. It seems crazy to not advertise it to the current biggest market for that kind of device otherwise.

I suspect this isn't quite the reason, but that there are reasons beyond it.

That seems like it's just a setting. If it turns out that it's a problem, Apple could release a patch that lets users define a safe "gaming volume".

It would be different if it were a design issue, like "can't be used for dark immersive gaming because too much light leaks in".

The vision pro doesn't have controllers so by default 99% of VR games are unsuitable for it so might as well focus on other stuff while they figure that out. People are definitely going to make games for it with eye and hand tracking.

Makes sense, the vision pro is a device created for people ready to take the next jump in computing, for people with the funds and the desire to be a beta tester in a new compute space. It's not meant for gaming power users.