Here's why. The consumer protections in the president's proposal ban the exclusion of individuals with pre-existing conditions. That means I can get insurance at any time. So why would I choose to pay thousands of dollars a year in health insurance premiums if I could pay the minimal fine each year and get insurance—no questions asked, essentially—when I got sick? I wouldn't, and neither did loads of people in Massachusetts when a similar low penalty was enacted.
The result is that nearly everyone will be "covered" whether they're insured or not. They'll be treated, and someone else will pay the cost. That's the way it is now, and that's the way it will continue to be if these bills pass—just under a different mechanism. Premiums from commercial insurers will be sky-high, if commercial plans even continue to exist long-term. What better way to get the deeply unpopular public option back in the mix in a few years?
And even if commercial insurance doesn't go away, it certainly won't be cross-subsidizing the government payers' underpayments anymore. So then there's no other option but the public one, which, oh yeah, has supposedly been taken off the table. Forgive me for seeming cynical, but some of these regulations, it seems to me, if enacted, will leave no other option long-term than—you guessed it—the public option.