People, for reasons of their own, often fail to do things that would be good for them or good for society. Those failures—joined with the similar failures of others—can readily have a substantial effect on interstate commerce. Under the Government’s logic, that authorizes Congress to use its commerce power to compel citizens to act as the Government would have them act. That is not the country the Framers of our Constitution envisioned.
Everyone will likely participate in the markets for food, clothing, transportation, shelter, or energy; that does not authorize Congress to direct them to purchase particular products in those or other markets today. The Commerce Clause is not a general license to regulate an individual from cradle to grave, simply because he will predictably engage in particular transactions. Any police power to regulate individuals as such, as opposed to their activities, remains vested in the States.This will be strong precedent for invalidating future "mandates." Congress could still go ahead and mandate things via a "tax," but they'll get called on it more often, and won't be able to deny that what they're doing is raising taxes. Because Congressmen don't like to raise taxes (or rather, people don't like Congressmen who do), this ruling will provide some restraint on future government action to compel Americans to do something.