I think Apple defined it by taking a tactile interface that can be used by a child or non-technical grandparent, replaced the iPod and a cell phone, great web browser, apps[1], and had a ready made ecosystem in iTunes and iPod accessories. Blackberry didn't get the combination[2].

Your right, it was more complicated, it was a combination with a little bit old and a little bit new.

1) partner apps first, third-party later

2) although some of "future" videos they made seemed to get it, but alas future videos don't make future products.