And this is the problem. There is zero thought being given to different usage scenarios, and when it is, it's a chaotic solution that works some of the time. How do you middle-click-paste if you are on a trackpad with only two buttons, for example?
I'm only picking on this to illustrate the point: things are hacked together at almost every level for a workstation. This is why "The Year of the Linux Desktop" never happened.
In stark contrast, I am much, much happier with Linux as a server machine than as a workstation, and prefer it to any others.