Its funny I see so many more DIN 5 connectors than mini DIN 6 in my collection, I tend to forget PS/2 had frequently unused pins.
Either PS/2 had a somewhat short run as the primary keyboard connector before rubber domes became the thing, or all the PS/2 mechanical keyboards are still being used so I can't buy them cheaply.
It makes sense though, pins that aren't there can't bend or break off