Let's not forget that Rory had a 2 shot lead going into the final hole. It would have taken a miracle for anybody to tie him, and no miracles were going to happen in that twilight. All Rory had to do was play it safe, get his par - even if either of the two guys ahead of him birdied - and that's what he did.
And it's not just "corporations" that would have been inconvenienced if they had come back to play one more hole, or half a hole, the next day. What about all those "little people", the volunteers, many of whom had to be back at their jobs the next day? The parking lot attendants, the concession workers, the greensmen, the list goes on and on. All of them would have been forced to come back early Monday morning just to watch two guys, one of whom was long out of the tournament, play one hole, and all the winner needed was a par, which he could make with his eyes closed. And he nearly did just that in the growing darkness.
Nope, they made the right call. And it was, in fact, Rory's call to make.