[dredmorbius]

This.

As much as I recommend that a serious power user learn and use a solid shell (bash or zsh, as my earlier comment suggests), several nines worth of users probably never will do so. Many could, though it's still probably somewhere between 10-25% of all users who would really have the aptitude to do so. And I do feel that the time invested in learning good tools on a well engineered platform pays of in spades.

That said: general-purpose computers are hard to use, very complex, and far more users know how to use them in some small way but really have little or no deep understanding of what they're doing or why. It's something that the tablet/handheld market's addressing, though I fear that the inclination to turn these into pure consumption devices will ultimately torpedo this goal.