[kevin_thibedeau]

> t's impossible for USB C to be hooked up backwards by its mechanical design, so why guard against it?

Because cabling can fail in other ways. A short could be caused by mechanical damage to the cable anywhere along its length. It would be nice to have a host that doesn't burn up in those scenarios seeing as they are already required to protect the bus.

[krapht]

Like other comments have mentioned, a short is not a voltage reversal. The methods to alleviate them are different. As the connector is polarized, the only way to get a voltage reversal is for something seriously strange to happen either at the power supply end or the cable.

If it is at the power supply end, all bets are off. If your USB charger fails short prepare for mains voltage to absolutely fry anything and everything connected to it and a negative voltage is the least of your worries. In the cable, a miswiring is seriously negligent and I see no reason why it should be designed around.