Why Don't Voters Revolt Against Single Payer?

Critics of single-payer health insurance systems insist we will all end up like those poor souls in Canada, France, Great Britain, etc.--waiting endlessly for critical tests or procedures, being abandoned if we're too old and sick for the government to care, and other warnings about the perils of rationing. If this is true, answer me this: Given that these are all vital democracies, why haven't the voters revolted and put into power politicians who will restore a superior private health insurance system? Certainly the politicians here are scared out of their wits making any changes to our current system--which rations care by leaving tens of millions uninsured or underinsured. Don't those same political dynamics come into play in other countries, or is this just a red herring--a scare tactic meant to discourage formation of a public plan option? I eargerly await your views.