Suppose the government made a law requiring everyone to buy broccoli or the IRS would collect a penalty from them. Would that be a constitutional, legitimate use of the “taxing power”? I don’t think there is a serious person who would say so. Yet that is exactly what Roberts held.
A criminal law requiring everyone to buy broccoli probably would be unconstitutional. At least I would hope so. But a tax on everyone, with a corresponding tax credit if you buy broccoli, is no different than things that are already done in the tax code.
You pay income taxes at a certain level. But if you have a mortgage you get to subtract mortgage interest and lower your taxes. Is that a law that requires everyone to have a mortgage? No, of course not. Same thing here. You don't have to have health insurance. But if you don't you owe an extra amount on your taxes.
The court could find no logical way to make that into something other than what it is. A tax to pay for health care, with a tax credit if you already have insurance. As I've already said, this new case is something completely different.