I think Leonhardt is maybe half right or maybe even three quarters. He's right that the choice isn't between rationing and not rationing. But I don't agree that the choice is between rationing well and rationing badly. I don't know what rationing well or badly means. He means we ration badly because we spend too much. He's right. The current system doesn't let prices ration. Prices are artificially low. There isn't enough rationing in the global sense.
For me, the crucial question is who does the rationing, a centralized decision-maker or a decentralized system. Centralized decision makers influenced by political pressure inevitably ration badly. Decentralized systems can potentially avoid the problem of political pressure.
The "reformers" want more top-down rationing with prices playing a smaller role than they do now. I want prices to play a bigger role. Prices also play a role in rationing any overall level of care among individuals.