"Why should someone who doesn’t take care of their body get the same rate as someone who does?" - from discussion about health care on Facebook. Below is my response.
I wish we lived in a country where we had this kind of problem to solve, but we're so far from the point of rewarding self-care and preventative care that we're treating birth defects as if they're the baby's fault.
Until the Affordable Care Act was passed, insurance companies could simply refuse to provide coverage for people with preexisting conditions ranging from the category of conditions you're probably referring to (smoking leading to cancer, poor diet and exercise leading to diabetes or obesity) to congenital heart defects, scoliosis, FAS, or other genetic defects that a person can't do anything to prevent. Also in this spectrum is damage from accidents that are likewise not under a person's control. Even if they provided some coverage, they'd often either exclude coverage for symptoms they deemed to be caused by a preexisting condition or charge incredible amounts for coverage to the point where it's beyond most people's ability to pay.
The reality is there's no amount of self-care or personal responsibility that will prevent needing access to the most expensive and inefficient health care system in the industrialized world at some point in your life. The Affordable Care Act recognized this and moved us towards a system whereby the treatments are considered the same regardless of the causes, and prevented insurance companies from choosing who lives and who dies based on a profit motive.
It's a step in the right direction and the best we could get under the political circumstances at the time, but we need to go much further in order to truly take care of each other and make sure everyone has a right to be healthy.