Right, the only thing worse than USB was the PS2 port. What sort of madness drive someone to invent a round connector that is keyed.

Hyperbole aside, there are some very good reasons to go with round connectors, it can be very strong and you can put a big nut on them to have an extremely secure lock. however the PS2 connector is nether of these things, It would require a much more robust key to work well.

The worst connector I ever encountered was on a old ATI capture card, it was the same barrel as a ps2 connector but had about 15 pins. Everything had to be perfect for it to insert, a tiny scratch or a slightly bent pin, it was not going anywhere.