That's not correct.
You are confusing the way the penalty for non-compliance is measured with the incidence of the penalty.
The mandate is not TRIGGERED by the receipt by a taxpayer of an item of income or gain. If it were, it would indeed be an income tax.
The mandate by its own terms applies to people as a class, subject to certain class exemptions.
Where the income test comes in is in the measurement of the penalty.
In a way, it is reminiscent of the way fines for breaking traffic laws are imposed in certain Scandinavian countries.
There, if you are caught for speeding, the amount of the fine varies depending on your income. Higher income individuals who break the speeding laws pay a higher fine than lower income laws.
Technically, that does not change the traffic law into an income tax.
It's the same situation with the ObamaCare mandate.
A very finely stated rebuttal. Thank you kind sir. /hattip