So I guess at least their unit isn't defective - it's by design. It's actually the BFP that doesn't fully comply with the USB2 specifications.
When the USB 2 specs were still up, the spec read "minimum 500 mA".
If the connected device draws more current, it needs it's own power supply.
In general, most laptop ports don't provide more than 500 mA, but some desktops do. The one that keeps lingering on in my mind, is Apple's G4 Cube, that provided 2200 mA, because Apple's external audio interface needed it. That interface doesn't work with any other computer, as there's no connector for external power. It is, however, Audio class compliant.
Some harddisk manufacturer's sidestepped that problem by providing a Y-cable, drawing power from 2 USB ports.
The USB 2 specs have been taken down and replaced by the USB 3 specs. And those are an entirely different kind of animal. They're so vague on several points, that Microsoft first decided not to include an Audio class driver in Windows 10.
MB Pro - FireFace 400 & DigiFace USB
ADAT gear: Korg, Behri, Fostex, Alesis
Appsys.ch ADAT over UTP