The reason the US is giving the whole country COVID is simply because the bourgeoisie are not human.

That is to say, the only concern here is capitalist economic self-interest. We live in an era of quarterly earnings reports. Even though mass death and disabling is obviously bad for the economy in the long-term, sufficient disease response appears more expensive to the capitalist due to short-term up-front costs (same reason America still uses diesel locomotives). To the inhuman bourgeoisie, the "culling" of "expensive" disabled people is beneficial. This is also why assisted suicide in Canada has been expanded into a eugenics program.

Now I emphasize "concern" because there are two reasons for why the capitalist world system has gone with infinity COVID over zero COVID. They can be summed up as capitalism, however.

1. As mentioned, a perverse focus on the short term gets you perverse results.

2. Capitalism is inherently incapable of dealing with pandemics. You need a global, centralized response.