The issue is that this doesn't fix the problem. It's just removing Stored Power because it slightly reduces the number of viable Baton Pass teams.Psychic is so underpowered compared to Stored Power that it's like taking Huge Power away from Azumarill. Anything benefits from a boost, but we are all talking about one specific team that uses a handful of specific sweepers.
However, Stored Power is not a broken move, so banning it would be a Very Bad Idea.