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.
Welcome to the world of tomorrow!
I'm having the same issue at work at the moment. When I connect to my dual monitor setup at work, all my usb devices stop working. Mouse, keyboard, the internal camera, monitors... All dead till you reboot, then they work for 10 Minutes again.
Now i have the same Monitor setup at home, no issues here. Mind you, it's a Lenovo ThinkPad with Lenovo monitors and it worked for years without issues.
The Lenovo technician told our IT guy that's because my monitor setup at home is another generation with a different chipset in the usb hub/switch. After giving us a few tips that didn't work, like disconnecting the Monitors from power for a minute or using a different port on the notebook they defaulted to "You're shit out of luck because the support ends after 4 years" - The monitors are 4 years old.