Unions are evil for the same reasons monopolies are evil. It's no coincidence that many if not most of the big union bosses are mob-connected. Compensation is tied to productivity, not unionization. That's why Detroit has become a ghost town. The great growth in union membership has been among civil service protected government workers. Both FDR and George Meany recognized that it made no sense to unionize government workers since no one sits on the other side of the table.