Where Leftism fails

Why does Leftism fail when it comes to health care? One reason could be the following facts (source):

Health care can have a zero price to the user, but that doesn't mean it's free or has a zero cost. The problem with a good or service having a zero price is that demand will exceed supply.

When price isn't allowed to make demand equal supply, other measures must be taken [for example queuing].

If Leftists would learn to understand these facts they might start to realize what is wrong with "free" health care. If they could in the process learn to understand the basics of the free market, and back off a little with their distrust in the human being, we might be seeing some progress in the future!