If still want a more “legalized” answer, you might have found it by using the search function:
Healthcare Individual Mandate Constitutional:
As recently as 1996, the Supreme Court reiterated the crucial distinction between a penalty and a tax. It ruled that “[a] tax is a pecuniary burden laid upon individuals or property for the purpose of supporting the Government,” while a penalty is “an exaction imposed by statute as punishment for an unlawful act” or - as in the case of the individual mandate - an unlawful omission. The individual mandate is a clear example of a penalty, where Congress requires people to purchase health insurance, and then punishes them with a fine if they fail to comply.
Therefore, the mandate is not a tax because the mandate pre-exists the government expropriation of funds from the individual. Ergo, it does not follow that “taxation is constitutional, so a mandate is constitutional.” The mandate is unconstitutional because it is not a tax, and nowhere in the Constitution does it say anything about the government being allowed to create such a mandate.
I do realize this doesn’t address your overall concern head on, as you’re whole thing is “if the result is the same, how can one means be constitutional, and another means not constitutional.” But (a) I addressed that above, and (b)…just think about that.