Corrosive Gale/Ratchet Bomb
2 Good Examples of sweepers that effect tokens but do not effect other weak creature builds.
If they just printed one card with similar type of sweep strength vs tokens it would all be in check, but they didnt, so they banned them.
If enough work was done in R&D that type of card could have been printed causing no need for the ban.
But it is what it is, ill save my heavy arguing for when they start banning good cards for no reason in a real format.