I assume by "mattered" Gruber meant mass market popularity, which IMO was mostly because Apple did get many things right in their touchscreen. (I owned a bunch of touchscreen devices before my first iPhone and they all sucked from a user experience perspective - missed taps, sluggish response, lack of multitouch, requirement for a special stylus etc).

Whether or not you like the iPhone, it's rather hard to claim that it didn't revolutionize the cell phone market.