This is the same reason if I can Mind Control a creature with a Mordok's out and then during the upkeep choose not to pay Mordok upkeep I can get rid of the creature and not worry about the MC.
During the Upkeep Phase, the upkeep cost for Mind Control must always be paid first, before any and all of the enchanted creature's upkeep costs. If you cannot pay, or choose not to pay, the upkeep cost for Mind Control, then Mind Control is immediately destroyed and the enchanted creature's control reverts to its owner, and any upkeep costs for that creature (if any) can be paid by the new controller.
This ruling makes no sense. There is nothing in the rules or the text of mind control that would make it go first.
Its is a clarification.
Probably because of it uniquely being a creature that doesn't belong to you. First you either choose to continue controlling the creature or not. Then choose any other upkeep effects in any order. If you choose not to control the creature any longer then the player gets it back and they get to choose any additional upkeep effects... making it unfair to the mind controller is the only way to make it fair for any future controling cards (which of course should have this timing specified).
Why do plants trigger bloodthirsty but they cannot have the bleed condition???
Just a point that they did erratum it in the FAQ. And that not all rules make sense...example of how plants DONT bleed but trigger BLOODthirsty. Which is why the rules don't always make sense.
Since Arcanus made a contrary Ruling in March of this year I would like to hear his thoughts on the subject.