>>20335549Because moves and abilities are generally designed for in-game (ie: singles) gameplay. More people play singles online than every other format combined. The idea that GF balances around doubles is absurd, only a small minority of players even touch VGC, and it's run entirely by TPCI, not GF.
Besides, if you were paying attention you'd have known that GF has no idea how to actually balance the game. They came out and admitted that no one had even considered special Aegislash when designing it, and that's the one Pokemon that actually appeared to be made with competitive in mind.