Of course the two locations you mention are more awkward for midweek, but this one was avoidable. Weather affected matches are one thing but this fixture change was simply down to the ridiculous situation with the football authorities. If we had drawn any other team the we would have been playing at 3 pm on Saturday. But because Hearts are a PL side they should never have been in this round as their season starts that weekend, whereas all other leagues are the following weekend.
So, because of the ineptitude of the people who run the game whoever were drawn against Hearts were going to have a fixture change. That was obvious as far back as May. For a professional side in the Championship it wouldn't have mattered for their players, as they are full time. But for all part time clubs this situation was going to cause a disruption and difficulty for players having to get time off work. Bobby Linn has already commented on this.
You are right that Edinburgh is not a huge journey and it would have been worse for Elgin (or Brora if they had beaten Montrose), but is is an unnecessary fixture change that could have been avoided if the powers that be, had thought ahead.
That said, I do believe that they are looking at resolving this before the draw next year.