Is waste, fraud, and abuse taken into account at all in this study? What about the inevitable changes to consumers' motivation, behavior, and decision making around healthcare? It will change drastically as the cost of their care is even further removed from them than it is now.
People who have a proclivity to go to the doctor too much will go even more when its 'free'. Younger people who eschew doctors because it interferes with their current lifestyle will feel even safer continuing bad health habits because free care will be there for them later in life.
Why should I subsidize other people's bad decision making?
EDIT: All healthcare is really too broad of category for government funding. Obvious things like cosmetic surgery and others are already excluded from consideration because they are not necessary. But IMO even when medical care is necessary I don't think it always falls into the category of something society should pay for. How many ER visits, ambulance rides, and surgeries a year can be attributed to purposeful recklessness by an individual? If someone decides it is a good idea to stand on a motorcycle's seat on the freeway and then crashes, why should the public pay for that? On the other hand people who have medical issues that are no fault of their own do deserve care.