The old dock connector, and the new "lightning" connector do a lot more that is supported by a USB connector. The dock can carry audio, video, act as a USB slav

The old dock connector, and the new "lightning" connector do a lot more that is supported by a USB connector. The dock can carry audio, video, act as a USB slave, and connect other slave devices. Arguably, Apple could have included both ports, but that increases cost and complexity and flies in the face of the Apple aesthetic.