It's all in the way the question is asked. When asked if the health care system in the US is good, most people will say yes, because most people have insurance. However, when asked if they want Congress to pass a health care reform bill that includes a public option, most people will say yes to that, because most people are aware that a public option will decrease health care costs, and because they are aware that there are almost fifty million people in the US who don't have access to health care, and they don't think that is a sustainable situation. They are also aware that while they may have insurance now, if they lose their job or get sick, they will lose their insurance. So while they may think they are getting good health care now, everyone with private insurance is at risk for losing it, and being denied coverage in the future. Thus it is in everyone's best interest to have comprehensive health care reform that includes a public option, and the majority of people know it.