> We really don't have an easy way in the modern era to share our PC's in such a way that multiple users have their own keyboard/mouse/video combination...

> But I guess, if there were a distribution which sets things up so that 4 or more people can use the same PC, it'd get wider adoption...

That makes no sense, for a few reasons:

The shared computer model is generally replaced by RDP (or similar) to a VM running in the cloud.

Vast majority of people use laptops or other portable computers; using networked applications where resource sharing happens "in the cloud": IE, web applications. The portability of laptops trumps stationary computers.

Furthermore, with modern economics, the computing power to do basic computing is so cheap that "dumb terminals" don't make sense anymore: A computer powerful enough to run a web browser costs about the same as what it would take to make a "dumb terminal".

Remember, a typical smart TV is a computer powerful enough to run a web browser or a general office suite.