Bear in mind at the time he was talking about USB 1.1 which was still prevalent on PCs at the time. While USB 2.0 was technically available when the iPod was released, it wasn't commonplace yet.
When USB 2.0 became more standard, Apple switched to it for the Mac+PC iPod. iPods could do USB or Firewire at that point, but Firewire was eventually dropped as a cost-saving measure.