Well, that's because they probably know one of the ports is Thunderbolt one plain USB.
USB-C only appears to make things easier, actually it's all fucked up, sure the ports are the same, but you have no chance of determining what's behind it by just looking at it.
But surely there's the advantage of only needing one type of cable? Well, only if you're willing to spend extraordinary amounts on your cables, there's a reason for the extreme price differences. You don't know if all the pins are connected, the shielding may be different and if you choose wrong power rating, your cable may overheat. So to sum up: you still need different cables, but now they're undistinguishable.