[ajross]

USB devices are supposed to be detected via the class (es) declared in the descriptor actually. This allows for e.g. a single HID driver to work with input devices from all manufacturers. Linux drivers almost all work this way, using the vid/pid for quirk detection only. The windows world tends to be less clean.

[jmaygarden]

That falls flat for custom/vendor classes. It's a fairly convenient route for a device that doesn't fit the other molds using libusb/WinUSB drivers.