Also, people with high deductibles should make sure you take advantage of tax benefits, HSA for instance. The $6000 deductible may really only be a $4800 deductible once you figure in the tax deduction. If you're talking Obamacare coverage being 20% higher than the penality (I'm assuming the penalty is not tax deductible) that may end up being a wash and you're better off with the coverage.
Now consider the guy paying the $1800 penalty instead of the $2900 coverage. The coverage being effectively $2175 (considering a 25% tax break). He pays $1800 for nothing instead of $2175. Passing up $375 coverage. Again, Obamacare - pretty much a debacle as far as costs - but that guy maybe not be the wisest choice.