If you want to move in the direction of trying to control for other factors, and thereby tease out a residual for "quality of governmental response"... then I'm OK with that, at least in theory! In practice, which variables to pick from is a hard problem.
For instance, it's easy to think of some disadvantages the US has, also. Lots of international visitors. Many people with pre-existing conditions. Higher average household size than parts of W. Europe (though low compared w/other regions). Also, NYC is its own unique beast.
There's also likely to be a fair amount of almost literal randomness/stochasticity in outcomes. If a group of tourists from Bergamo decides to visit NYC rather than Toronto in February, that could make a big difference. Also, there may be different strains of the virus.
Anything that moves us in the direction of acknowledging that this is a messy, noisy, nasty problem—and policy choices and political leadership are only one of many factors—is something I'm a fan of. That does a better job of reflecting the outcomes we're seeing in reality.
