I think few people want the system as is. It's a combination of a) thinking this doesn't affect you because you have good insurance (until it does, becase something like this happens), b) not realizing just how fucked you are because you don't have insurance but haven't gotten seriously sick yet, and c) simply not realizing things could be different/better.

Particularly for the last point, socialized medicine is often weirdly spun as bureaucrats taking away your freedom of choice and preventing you from getting health care ("death panels" and all that). So people visualize the current fucked-up system, imagine what it would be like if they had even more obstructive bureaucracy dictating whether you're allowed to get surgery and how long you need to wait in line, and often course they think that sounds even worse -- although the reality is that would be better for most people than the status quo of only being able to get surgery if you can afford it, and still risking getting bankrupted in the process.