I thought they made the reasoning behind leaving the lights on a little longer rather clear. They understand that Final Fantasy XIV is more than just a game, but a place for its community to gather. Gamewise, yes, it's fruitless to level up if none of it's going to be saved. But for anyone who does any form of socializing in-game, it makes a little more sense.

I don't see the harm in leaving the lights on for those who'd get any use out of it. You can't argue that it'll make ARR take longer to get here because they also clearly stated that after the final save, all support for the old structure is done and gone. They might be paying someone over there on the physical end to make sure the hardware doesn't catch on fire and to "turn it off and back on again" when needed, but as far as the dev team goes, they said no more patches, support, etc.