It was "forbidden" to be collected like a tax. They could not garnish for it they could not penalize you for not paying it...it was not to be considered a tax.
The U.S. Supreme Court didn't forbid anything. That's the way the statute was written ... which was just one of many incoherent, idiotic things the law contained.
Thats correct: the SCOTUS did not forbid anything. The SCOTUS said it was a tax after the law went out of it way to say it wasn’t.
Poorly written, yes. But that was one of the arguments: it wasn’t called a tax so it wasn’t: the law laid out defined taxes and the mandate penalty as not one of them. Roberts saw fit to say it was and then ruled it legal.
Near as I can recall and I am not a legal eagle, that is why this mess is still with us today.