Because, here's the reality of healtchare in America.

So long as it is not something the government guarantees to all, it will be available only to those who can pay for it, or who fall into those actually few categories of inidividual who the government will pay for.

That means there will be those who cannot afford it, and therefore will not get it.

When we, as a nation, say in any way that we will not do what is necessary to make sure people can get it, regardless of whether they can pay for it, then we are saying that there are some people who somehow do not deserve healthcare, or, are tough out of luck and should go untreated for whatever reason, or, who we can discard onto a heap (for some reason) as not worthy of receiving healthcare.

That's just an enormously uncivil, cynical, if not evil view.

I don't like lots of people.  But, thinking about it meaningfully, I could NEVER bring myself to decide ANYONE should be DENIED healthcare - just because the don't fit into my world.