Some software will not recognize 3rd party USB 3 drivers in Windows 7. This will be the case even if the drivers are fully functioning.

For example, I have a 2013 motherboard which was top of the line for desktop systems at the time I got it. I run Windows 7 on it with the manufacturer's drivers installed.

The USB 3 devices plugged into USB 3 ports are recognized and function correctly. But when I run VMWare Worstation 11 on it, it does not see USB 2 or USB 3 devices plugged into USB 3 ports. The same devices are recognized by VMWare workstation on a Win 8 laptop when plugged into USB 3 ports. And the same devices are recognized by WMWare WS 11 when plugged into USB 2 ports. If the motherboard did not have USB 2 ports, I would not be able to pass through to the guest OS any USB devices at all.

VMWare did start supporting USB 3 devices under Win 7 starting with WS 12, but it came out only in 2015. But I haven't tried it. And I don't know if it will support the particular 3rd party USB 3 drivers which I have.

From a developer perspective, I have to mention that USB 3 ports are functionally very different (it's not just a difference in speed) from USB2. So the decision not to provide generic kernel-mode USB 3 drivers in Win 7 may have more to do with how the USB driver framework was designed in Win 7 vs Win 8. If the whole framework would need to be overhauled in order to support the drivers, then MS was probably justified in asking that a later version of the OS would be used.