The big iMac had a little baby iMac. Time Machine did its thing with a minimum of fuss and normal service has been resumed. Will entertain TO's eminently sensible proposals for Mac Pros driving multiple 32" 4K monitors at a later date.
My trusty old iMac bit it hard today. Took it in to the local indie reseller/tech but not optimistic. Also not a great time as we move in a month and I don't want to 1) replace in SA where they're very expensive or 2) replace right before the rumored Retina models come out. So 3) balls.
BRB, super busy starting my niche business offering audiophile Lightning-to-TRRS adapters.
From the device manufacturer's standpoint, it makes perfect sense to just use the one hole. People tend to have stubborn individual preferences though. (Down, Steve.)