I can appreciate what you're saying in the last paragraph. However, I disagree with the concept of "if I opt out, I shouldn't have to pay for those who opt in." Simply: if you don't pay in, and then need it at some point in the future, you're imposing on those who opted in in the first place. You're the one getting something for nothing, and everyone else is paying into it for you.

The Amish have pretty much perfected this when it comes to social security: they support each other as an intentional religious community. Therefore, they have a religious exemption for paying into SSI, etc., because even if they get a job outside the community, they don't use the government as a religious/community principle. They have that insurance built into their way of life.

Most people don't have that kind of guaranteed quality of life insurance. Therefore, I believe that anyone who realistically might have need to access the system -- including ex-Amish -- should pay in. It's how SSI works (in theory; I won't go into how broken SSI is at this point), so I have no problem applying the same concept to opt-in universal health care. In general, you don't plan to rely on SSI for retirement or if you become disabled, but if it happens that you need it (and can jump through the hoops to qualify), you're damn grateful you don't have to beg for that little bit of extra support.