2000: Can we sell this tablet (or phone)? - NO, because hardware isn't good enough and even if it were, why would anybody buy this, if they can't watch movies or listen to their music without too much hassle? Let's build a music (& movie) store, so that when the hardware is ready, we are ready too.
2005: Can we sell this tablet (or phone)? - No, the hardware is good enough now, but we need great software too. Let's build a great mobile OS (from scratch) and leave the legacy behind. And give the 3rd party developers the SDK and tools to build great apps for our device.
2010: Can we sell this tablet? - YES, the software is great now, just like hardware. Order 15M iPads to Foxconn and ship the damn thing!