I think you're discounting the performance aspect as well - if workload X is too slow on the fastest mac, it may well still run on a windows machine since they can be specced higher. Cost isn't a factor for everyone - sometimes you literally just need the fastest possible machine, in which case Windows can be it.
Am I missing something or does this seem like one thing? Or is there use case for VR that isn't gaming? And what is 'upcoming 3D' exactly?
>if workload X is too slow on the fastest mac, it may well still run on a windows machine
Can't argue with that, but what are such workloads if you are not game developer? Wouldn't cluster of Linux servers always be a better choice? Unless of course you are die hard Windows fan.
Training and design.
Presumably the author has already purchased the Mac, in which case, s/he's already obtaining the benefit from that purchase. To rationally justify the replacement cost (which is not just the cost of the hardware itself, but the opportunity cost of learning the new platform, purchasing new software, etc.), the benefits of switching have to be greater.
It's those benefits--not necessarily of the platform itself, but of switching--that aren't clear to me.