This move is hardly out of step with changing standards. Tail docking is already banned in Australia, many parts of Europe and now parts of Canada. In the U.S., however, not so much.
As of late 2014, only two U.S. states - Maryland and Pennsylvania - have laws on the books, which permit tail docking only in dogs of a certain age.
Among the main proponents of tail docking are kennel clubs, which consider docked tails and ears to be historical standards for some breeds. To that, the American Veterinary Medical Association publicly opposes both "when done solely for cosmetic purposes," and likewise encourages changes to such standards.