USB 1.0 seems like one of the many interfaces that will eventually end up obsolete just like ISA PCI AGP PCMIA etc...
I really don't see anything technically superior about USB (feel free to correct me). The main reason it won out over Firewire was of course Intel and Microsoft backing, and that it was in the sweet spot for the price/feature trade off.
So on the low-performance side, the advantage is clear. And end-users like the simplicity of having the same physical port for all their computer peripherals (which can use low- (<1Mbit), full (12MBit) or high (480MBit) speed, without the user knowing or noticing).
While I personally think that Firewire is the more elegant, better performing and more flexible communication technology, I can see why USB surpassed it in the marketplace.
[1]- Firewire lost mainly because the cheaper+slower USB1.1 became ubiquitous first, and then came the backward-compatible (in connectors/cables) and comparably-fast USB2.0.