Apple is basically Bauhaus for nerd stuff - and that is no small thing. Perhaps if the microcomputer had been first commercialised in Europe they'd all look like that anyway.

Personally, I view Apple more as a fashion house that sells tech.

Those fashion designers make a pretty mean little RISC chip.

If instead of "very easy" would you be happy if I said minimalism is the "least hard" to pull off?

Cue Kevin McCloud from Grand Design whose standard rant about minimalism is that it’s actually the hardest to pull off because you aren’t hiding behind anything. All of your decisions are exposed, so you have to be even more thoughtful about attaining cohesion in the final form. Of course, he is talking about buildings which is a different thing, but I think some of what he says applies to other design fields too, including UI design.