"Public option" means something different for every person. When you get down in to specifics, all of the sudden it's not the kind of "public option" many wanted.
That's really not true at all, at least not according to the polls. Most good polls don't even use the phrase "public option" anymore. The WaPo poll's language is "having the government create a new health insurance plan to compete with private health insurance plans", which is pretty specific, and even more specific poll questions have resulted in similar numbers of support.