This has nothing to do with obamacare and more to do with capitalistic insurance companies, in my opinion. All Insurance companies do is look at income vs risk...if you do things that increase your risk level, your cost will increase such that the insurance company is making a good profit margin off of you. It's really not that complicated. If the company wants to make X dollars off of you during the term of your policy, and you do things which may increase the rate at which they are forced to pay out, your premium will be higher.
Take for example the two people below:
Person 1: Buys insurance X @ age 10, has no risk factors for health issues, does not smoke.
Person 2: Buys insurance X @ age 10, has family risk factors for cancer, smokes heavily.
Looking at these two people, which one is more likely to pay their premium without making a claim for the longest period of time? Obviously it's #1.
Here's a math version:
Person 1: buys policy @ age 10. lives to 85. Pays $100/month for insurance.
That means that this person would pay the insurance company $90,000 over the term of his plan (This doesn't factor in premium increases as you get older, or claims...it's a simple example)
Person 2 on the other hand started smoking at age 16 (that's not an unreasonable age, sadly), and after 30 years of his pack a day habit, has lung cancer. what this means is that the window under which the insurance company collects without claim is much shorter (36 years instead of 75), and consequently, the insurance company will charge more monthly to make up the difference in profit.
In the above example, person 2 would have to pay $163/month to match the same profit level as Person 1 paying $100/month!
Pure, simple capitalism.