Turning over a substantial portion of the economy to the government is a lot to ask. Private sector jobs will be lost, healthcare providers will face additional workload, and a transition that large, no matter how well managed, will have its rough spots.
The disastrous Obamacare rollout comes to mind, for instance. Even a popular government might think twice before taking a task like that. But asking the public to trust a largely unpopular government with that much responsibility? It’s easy to see why many voters might say ‘no’, and why many politicians may not want the headache.