I think the difference is actually because Tim Cook doesn't care about design. I can't find the link, but I heard when they launched the new Mac Pro, Ives trie

I think the difference is actually because Tim Cook doesn't care about design. I can't find the link, but I heard when they launched the new Mac Pro, Ives tried to show Tim Cook what it looked like, but Tim responded with "I get it... its a computer", and didn't see the design until the public launch event.