I'm explaining his argument, which you mischaracterized. But excuse me Mr. "I've read a few articles and now I'm an expert on Con Law."
There has not been a court ban on congress achieving regulatory goals through taxation (and that IS what the fine is) since Bailey vs Drexel Furniture in 1922, which invalidated a 10% tax on the annual profits of companies which knowingly employed child labor. But the
only reason the court ruled that way is because the court viewed the law as an attempt by congress to circumvent the court overturn of another child-labor-related law from a year or so earlier.
The court even upheld a regulatory tax designed to completely eliminate bookmaking operations in 1953, and a tax that compelled states to create unemployment benefits systems for their residents in 1937.
The mandate is essentially a regulatory excise, which congress is given power in article 1, section 8
No part of the constitution makes a distinction between congress's regulatory authority over private or public commerce. Furthermore, the companies which provide health insurance are all government-created corporations, chartered by the state governments. Though the concept of a corporation did not exist when the constitution was written, the idea that the government can regulate activity between persons within its jurisdiction has been a prevailing idea for millenia, and the same concept applies to non-personal entities.
Whether they're fining you for not purchasing private insurance or taxing you for a government-run health insurance program that you 1. Are not allowed to use until a certain age. 2. May never be allowed to use in your lifetime and/or 3. Are not required to use when you are permitted to, they are regulatory measures by congress over the territories it holds jurisdiction.
Please tell me what is unconstitutional about any of this. Please.