They don't have the option to enroll or not. They have to or they get penalized. The penalty is small; $95 per person, but this is really just another tax on a growing margin of society that can't shoulder more taxes.
The health care industry has already responded to the situation in a more sensible way. Many urgent care clinics have popped up in the last few years. They'll handle most run-of-the-mill health concerns for $100-$200 a visit. Many drugstore chains have started their own prescription clubs that cover a pretty wide range of common medications for very reasonable amounts.
If you're a healthy individual who visits the doctor twice a year and maybe you need a prescription or two, then it makes more sense to pay for your health care on an as-needed basis. You'll save more money. Obamacare didn't really solve the major issues with health insurance. They missed the mark because industry already stepped in to provide a solution. If they wanted to solve the problem vis-a-vis affordability for marginal workers, the solution would have been to make it free.
Just like with gay marriage and openly gay military members, we'll get there eventually, but people are still suffering because of the painfully incremental way legislature works.