First of all, this is a rules questions, not one of balance. Secondly, I don't make the rules, and even if I did, attacking me won't change anything. Thirdly, this isn't at all new, and it's not a ruling, not an interpretation of something that could just as well be interpreted differently.
So let's talk about the rules.
From the core rules:
"The capital phase is the only phase in which a player is allowed to play unit, support, and quest cards from his hand to his three zones (kingdom, quest, and battlefield). Only the active player may play unit, support, and quest cards from his hand during this phase. In order for a player to play a card from his hand, he must pay for it by […] A player is considered to be taking an action when playing a unit or support card from his hand (or when playing a card face down as a development) during the capital phase. The other player may still take actions (play tactics or trigger card abilities) during this phase, but only the active player is permitted to play unit, support, and quest cards from his hand."
Notice that it's always "… from his hand …", in contrast to:
"Players can take actions during any of the shaded “player action” boxes in the “Detailed Turn Sequence” chart on page 14."
From the FAQ:
"Playing a unit, support, development, or quest card from hand are actions with restrictions built into them. The restrictions are:
They cannot be played in response to anything.
They must be played during the owner’s Capital Phase."
When you are playing Judgement of Loec via Gathering the Winds, you are not playing it from your hand, and you are not playing it as if it were in your hand, like you do in the case of necromancy. Therefore, those restrictions do not apply. You are taking a normal action, in the course of which you get to play a spell, which happens to be a support card in this case. My original explanation stands, as does Entropy's.
Does anyone believe that Waiting in Ambush or Gryphon Legionnaire can only be used during your own capital phase? You would have to, by your reasoning.
If you don't believe Entropy and me, you will need to bother the devs with a rules question. Balance, or a supposed incredible lack of it because the High Elves can potentially play Judgement during the opponent's turn, is a different topic.