Since John Roberts decided to play politics and not jurist wrote his tortured and twisted opinion making the penalty for not getting insurance a "tax", the small amount of the "tax" encourages healthy individuals to wait until they get cancer of some other disease to enroll. The "tax" since it's now legal, needs to be more like 90% , or more, of what the average premium for individuals that age. Otherwise, no plan will ever work. Period.
The tax code is already full of financial manipulation of our choices. The only thing different about the Obamacare penalty vs. a thousand other things in the tax code is how it's applied on paper (as a penalty rather than a missed credit or deduction). I disagree with Roberts, but given the practically unlimited authority of the tax code, Roberts would be almost arbitrary to rule any other way. The tax code could be written to present the penalty as a lost credit, but it would be nothing but bureaucratic complexity to achieve the same result.
The penalty is already high enough to make Obamacare the money-saving choice. For most people who have jobs that don't provide insurance, the credit is enough to provide "free", or nearly so, insurance. I think Obamacare's problem is that the working poor are not as healthy as the working middle-class who get insurance through work.