Actually, doing a bit of homework it seems Roberts may have been correct in his ruling based on past case law.
See: United States v. Kahriger,Marchetti v. United States, and Bailey v. Drexel Furniture Co.
Since this is no longer a ‘mandate’ from the government, but some sort of ‘tax’ which will require a statement of self incrimination...it violates the precedence set in Marchetti v. United States.
This new aspect will need to be argued if the ‘tax’ ever get applied.
Bingo. This is just one of many, many aspects of ObamaCare that haven’t even been challenged yet.