Typical scenario where knowing little is worse than knowing nothing at all, lol
Never even had to bother with that back then.. but fast forward it to now and my needing an extension and.. have a look.
Tell me which one's wrong please, 'cause i'm lost. Notice how they're differently keyed?
So to answer my own question? Apparently it's just greed.. no one ever made an 'opposite' header, because no one ever minded using the same for both the male and the female! I mean why not, right?!
So while yes it looks confusing, because yes, the keys should be matching, in reality there's only one plug being made and it's interchangeable.