Host transmitted protocol packets are routed through intervening hubs directly to a peripheral device. They do not traverse bus paths that are not part of the direct path between the host and the target peripheral device. -- USB 3.0, section 3.2.3
USB 2.0 is broadcast technology, meaning that all devices on the bus receive all packets. USB 3.0 is unicast technology, meaning that packets are routed only to the target device.
Technically, shouldn't we be saying "USB 2 hub" and "USB 3 router"?