That's not entirely true.
Reverse polarity protection is very common, and often only requires a single diode in series with the +V line, so that current can only flow in one direction.
A diode will drop about 0.5-0.6 volts, which could eat 10% of your energy, so reverse polarity protection is usually used in devices where someone could plausibly install the batteries backwards. I think it's probably rare on something on a highly controlled standard connector like USB.
It's fairly easy to do it without the diode drop if you use a mosfet, but you do incur the cost of a more expensive part.
It's usually common in low voltage, low current devices. I have a massive inverter charger on our boat that has in giant letters "NO REVERSE POLARITY PROTECTION". It typically handles up to 200amps at 12V.
The cable attached to the Chromebook was totally miswired and flipped Vbus and ground, supplying -5V where 5V was expected. As the article said, nothing is really designed to handle this kind of failure because it should be blatantly obvious to the cable manufacturer if there were any sort of quality control.