Here is a simple fact..
If you areyoung and healthy, buying the insurance is a bad deal. If you get sick later, you can just go and buy insurance at that time. The most likely cause of harm, auto accidents, have medical costs in the insurance. If you have auto insurance, full coverage, there isn't a lot of need for it. If you do get hurt, you will be helped at the ER and can buy insurance after for anything you need.
I draw a parallel to auto insurance, with respect to good deal bad deal. I own a car, I paid cash for it, it is worth a little over $4 thousand. I went to get insurance for it, I had a dwi arrest a while back, and even liability was over $100/month. Full coverage was $140 or more.
Due to my recent addiction, I really don't have any assets I need to protect. So, what I've been doing is building a cash reserve. Buying auto insurance would hinder this effort. I now have about $6 thousand dollars saved up. If I get into an accident, I've lost my car, but at $140/month, it wasn't wort protecting. Coverage for a more expensive car wouldn't be much more. Buying car insurance was just a bad deal given my circumstances.
Same with most young people and health insurance. They don't really have much need for it, and the most likely cause of medical treatment, injury, is usually covered in their auto policy, or injuries at work in workers comp insurance.
Other than a law saying you have to have it, there is no good reason for most young people to have health insurance, so many don't, and won't.