Except its the opposite way when we are talking about Gothitelle and not Wobbuffet. Shadow Tag Gothi actually targets defensive teams more. Trick + Rest PP Stalls almost any wall, Charm + Confide + Taunt + Rest does the same, but can also kill something offensive and then there is Calm Mind + Stored Power, who, if traps a Wall, 6-0s everything that doesn,t have a Dark Type or a powerful physical Ghost or Bug.
I do think that having the ability banned is excesive (I don,t consider Gothita and Wobbuffet to be problematic Mons, unlike the big Goth) but your statement of it only being effective against HO is false.