More like watching people poison themselves willingly then turn around and ask other people to foot the medical bill for them. If you smoke, drink excessively, stuff junk food in your maw everyday to maintain an unhealthy lifestyle, then you should pay a much higher amount than someone who keeps an eye on his diet, goes to the gym, does sports, etc.
Just like car insurance, someone who has 10 speeding tickets, 3 accidents they cause, have a much, much higher cost than someone who has little to no speeding tickets or violations.