I wouldn't say orthogonal. Making something inviting, approachable and feel like a safe place to experiment/explore for a novice is a critical and overlooked part of usability. The childlike choices of "bright primary colours" and "no sharp edges" is one way to attempt that.
It's what the general public needs that us nerds can least relate to.
It might have been good for brand-new users and children, but not all computer users are like that. It would have been much better if they had had selectable themes.
> It might have been good for brand-new users and children, but not all computer users are like that.
Well, are you sure which of those groups you belong to? At least as far as Windows is concerned? Because:
> It would have been much better if they had had selectable themes.
It did. One click in the right place in the Control Panel and it looked like W95/NT4/W2K. (So did Windows 7, and therefore I must assume Vista, too. [Skipped that one myself.])
But, hey, brand-new users and children couldn't be expected to find that, right?
It's what the general public needs that us nerds can least relate to.