I think the other issue is mechanical robustness. μUSB, mUSB, and USB-C were engineered to fit on small devices like phones, cameras, and laptops. μUSB ports an

I think the other issue is mechanical robustness. μUSB, mUSB, and USB-C were engineered to fit on small devices like phones, cameras, and laptops. μUSB ports and cables fail all the time. mUSB and USB-C are better, but the large USB-B connector is king. The original idea was to have a few sizes corresponding to a few sizes of devices. For large devices expected to last many years, like printers, scanners, multi-drive storage devices, many types of pro-AV equipment (e.g. one of those pan/tilt/zoom cameras permanently installed in some lecture halls), scientific equipment, and so on, the square plug is king. You don't want to lose a $5000 device due to a failed connector. I mind having a proprietary cable for each device. I don't mind having a few types of cables as they make sense.