no, No, NO, N.O. The Court held no such thing.
The author does not understand the difference between a) "Chief Justice John Roberts concluded" and b) "Chief Justice John Roberts delivered the opinion of the Court." A & B are two totally different things.
'A' means Chief Justice Roberts opined (suggested, mused, theorized)
'B' means that the Court held (ruled, judged, decided)
With respect to the constitutionality of the individual mandate under the Commerce clause and the Necessary and Proper clause, Chief Justice Roberts suggested that because inactivity is not commerce, the individual mandate is unconstitutional. None (zero, zip, zilch, nada) of the other justices agreed with him. Therefore, Roberts did not deliver the opinion of the Court.
With respect to the constitutionality of the individual mandate under Congress' taxing powers, a majority of the justices (Roberts, Ginsburg, Breyer, Sotomayor, & Kagan) agreed that the individual mandate's penalty is a tax and is constitutional. Therefore, Roberts delivered the opinion of the Court.
That's because none of the other justices (zero, zip, zilch, nada) discriminated between taxpayers and non-taxpayers.
Read, and learn: How Chief Justice Roberts Saved America