Why are we forced to buy health care?

Obama wants to look good to the UN. The UN rates our health care poorly partly because we don't insure everyone. His premise is to insure the other 30 million who don't have health insurance. Still not everyone will have it for some unknown reason. Some of the 30 million don't want health insurance. Some really can't afford it because they earn too much for Medicaid and not enough to buy it out right. Some wouldn't be able to buy a home and car if they opted for health insurance. I agree there are better ways to deal with the problem than what our government has done to us. They know from the states who have used mandated health insurance that it is too expensive to deal with in that way.