I should clarify that "they" in this context is the consumer, who rejected Google Glass for a multitude of reasons, but embrace this product which is essentially the same thing, except bulkier. I can't really wrap my head around it.
This is vastly different than Google glass on many fronts.
Just to name the more obvious ones:
Higher quality output
Full visual
Both eyes
Internal face scanning
Eye tracking
An actual app ecosystem
The glass was a dev kit, at best, and funnily enough ran fairly close to the cost of the Vision Pro when you take inflation into consideration. And the reason it failed was more because Google lost interest and killed it, like they do with most of the things they put out.
I'd like to think that with a decade of time spanning between the Google Glass devkit and Apple Vision, had they chosen to continue development, that they could have improved on their initial design with technological advancements in hardware that would absolutely allow them to do a higher quality output in both eyes and incorporate eye tracking.
The main reason why Google abandoned the project (in the public sector, anyway) was the metric fuckton of negative press it was getting, mostly due to neo-luddites obsessing over the fact that it had an outward facing camera as if they weren't constantly under scrutiny and surveillance by cell phone cameras and CCTV anyway. The media coverage of the product was way outsized compared to the actual number of users. Another reason is people weren't convinced that this early heads-up device was worth the cost since as you mentioned it was expensive even back then, and most of the comments I saw about it at the time believed that the bespoke glasses they came with were dorky looking, not to mention lenses were not available in prescription strength, so yet another limitation that could have been overcome with a bit of engineering effort.
I don't disagree that Vision Pro is better, but it looks like a huge step back in terms of style and practicality. Who wants to walk around town with a VR headset strapped to their head? It really does look like the NPCs in Cyberpunk 2077.