True, but if it is levied equally, or "in proportion with the census," then it is constitutional.
But in this case the penalty is set as the greater of the minimum or 2% of gross income, plus there are waivers for those with incomes under certain levels; as such, the tax cannot ever be levied in proportion to the census.
Also, since the tax would not be levied on every individual pro-rata - it goes through the tax return so anyone who is not required to file a tax return is not required to pay that tax, such as minor children included as dependents on their parents' tax returns - it will necessarily fail the proportionality requirement even if it isn't set in relation to gross income.
Just in case it seems like I'm stepping on my own toes: I agree that if every single individual who is counted in the census is also required to pay the exact same dollar amount, then the tax would be a constitutionally apportioned head tax (i.e., a "direct" tax). All I am adding to the mix is that in this case the Obastardcare tax will never be that sort of tax and therefore will never survive muster as a properly apportioned head tax.