That still looks better, in my opinion, than the mobile operating of today. A proper dark theme many years ago, and an elegant (IMO), simple, touch-oriented UI. It avoided the "play skool/AOL" aesthetic that really rankles me with more popular UIs: rounded corners, circles that should be squares, etc.
All that said, I agree with the article's point that UIs that do not more clearly reveal the totality of their user interface actions are frustrating. I've often found iOS to be especially bad at this for outsiders like myself, especially with respect to hardware features outsiders are completely unfamiliar with such as "press harder than usual."
Windows Phone's aesthetic was certainly a welcome, effective change compared to iPhone's dominant paradigm. I suspect you'll pry rounded corners from Jony Ive's cold, dead hands.
I agree that iOS's "discoverability" is awful. I wish Apple had some head of UX like Android has with Matias Duarte. Instead, they put Ive in charge of software UX and it's clearly not something he cared about.
All that said, I agree with the article's point that UIs that do not more clearly reveal the totality of their user interface actions are frustrating. I've often found iOS to be especially bad at this for outsiders like myself, especially with respect to hardware features outsiders are completely unfamiliar with such as "press harder than usual."