It has nothing to do with "originalism," or the Commerce Clause, or anything else. He doesn't think that the people who would benefit from the law deserve to have a law that benefits them.

Here's the deal. I think Justice Antonin Scalia isn't even really trying any more. It's been clear for some time now that he's short-timing his job on the Supreme Court. The job bores him. All these inferior intellects coming before him. All those inferior intellects on the bench with him, now with some other Catholics who aren't even as Catholic as he is, Scalia being the last living delegate who attended the Council of Trent. Inferior Catholics with inferior minds. What can a fellow do? He hung in there as long as he could, but he's now bringing Not Giving A Fuck to an almost operatic level.