And people don't realize the extent of pre-ACA government intervention (employer-based insurance subsidies, COBRA and continuity-of-coverage rules, even Medicare), and they often don't realize what their plan costs if they get it through their job, and they don't know what their actual treatment costs are or why those prices are the way they are, etc.
It's a really complex issue that deals with maybe the most important aspect of people's day-to-day lives, their health. So even though FUD already comprises like 80% of political discussion, health care policy is even more fertile ground for it.