Actually, for Pro USB-C may be more appropriate. Mouse, hard drives, printers, scanners, imagine what kind of devices could be connected.
None of which I carry in my briefcase. I do however carry my iPad charger everywhere as I can use it to charge both my iPad and iPhone. Changing to USB-C would mean having to carry another charger and cable. It's stupid IMO. Not to mention all the iOS peripherals that would need adapters to work.
They should stick to one standard connection across all their devices. Let the USB users have to buy an adapter if they want to deviate from that standard.