How is VR different from a monitor Apparently Macintosh computers cannot handle the Oculus Rift, because of their 'inferior' graphics cards. But should VR not just be like an external monitor? And concerning computer graphics, how are VR games any different from other games the Macintosh can run easily?
Where is the problem?
VR requires a much higher resolution and framerate, and a much lower latency (start of draw to showing on screen).

If any of those things are missing then people tend to get nauseated. 

All of those require much higher bandwidth and compute power than Apple's cards are supposed to be able to handle.