Blizzard will just say that it's intended for new players coming to the game, not for people wanting to level alts, even though that's what everyone uses it for. Imo, give the 3x XP to accounts for 3 months that are involved in a scroll of ressurection. You let your account go inactive for a month, then recruit it back and get a few months fast xp. This solves the mass amount of accounts problem, but you just won't be able to do it consecutively on the same account, will have to wait in between.