Would people really buy an expensive Mac Pro just to play virtual reality games?
Yes
The PC gaming industry (not prebuilt computers, but components and self built / custom built) in 2016 was estimated to be approximately 35 Billion dollar industry.
This was helped by a LOT selling GPU's for $500-$1000 just for a single card.
gamers are willing to spend a lot of money to meet their own desired performance goals. If Apple provided a computer that offered that performance, There'd be a market for it.
Heck, you know what I would love? The Mac Pro tube in "gaming" format. Put in a consumer i7 instead of Xeon. Put in a Single Consumer grade GPU, with option to add a 2nd. Make them modular so that they're upgradable with newer gen GPU's, and the "Mac Pro" would have been the ultimate "Mac X"
Why the Mac Pro was a "failure" was it was giving to "professional" market, a device that could have been aimed at the "enthusiast" market.
the Professional market, tends to be geared towards earning money with compute power. This often comes with high storage demands, expandibility demands to keep up to date and profitable. But it often doesn't require "looks". In fact, the people who use their compute power to the fullest for their livlihood are going to generally care a lot less about the look of the tower, as long as the tower performs how they need it to, and can be kept up to date
Gamers on the other hand genreally have lower storage demands (they don't tend to keep all their games installed all the time, and will only keep their most played and current games installed), making the smaller form factor with single drive more ideal for gaming than enterprise professional work. They also tend to replace most of their parts a little less. Where a professional might need to upgrade CPU's, RAM or storage frequently, in gaming, GPU's are really the only thing that gets ugpraded semi regularly.
Gamers are also a lot more concerned with quiet, as noise distracts from gaming, or makes it harder to compete. Professionals? sure they might not want a jet engine, but they're far less likely to sacrifice performance for noise. Gamers are nuts for noise.
again: the Mac Pro was a lousy Professional workstation. But it's nearly ideal form factor and design for a decent gaming computer.
the Macpro is just another piece of evidence that showcases to me that while Cook might understand iPhone market and how phones and iphones fit into the world. He hasn't the foggiest thing about Computers.