It either needed to be cheaper or offer way more in terms of functionality. For $3500 it needs to be able to plug directly into a PC to be used for gaming and other applications that can't run directly on the headset.
It has screen mirroring, but that's pretty limited and can't be used for applications that need low latency such as gaming.
It seems the main selling point was to be able to use it for productivity. Set up a bunch of windows and work with them in virtual space. But for $3500 you could just get a bunch of monitors and some arms and have a much better experience.
You couldn't even take the headset off without all your windows disappearing and having to go through the entire process of setting everything up again, which could be annoying if you have a lot of applications open. Sure it has pass through so you can just continue to wear it, but sometimes you just need a break and want to take it off your head. Having everything reset when you take it off is just unbearable.