Opinion: Why the US has the world's highest number of Covid-19 deaths — CNN

No scientific proof but... Because we are genetically pre-disposed to tell authority to "piss off."

I would point out that there has been varying states of leadership among the various states and cities. Florida went sideways because they shortsightedly didn't close their beaches for spring break. New Orleans did also because Mardi Gras parades were big business.
But I'd look no further than California vs New York. California had the first known case of community spread back in February, and took steps to contain the virus. New York leaders decided that keeping businesses open and going to a show was more important. The contrast is stark.

Based on my own research the administration (POTUS) refused to take this very seriously despite briefings form intel community and some of his own advisers. His only focus is to be reelected. For decades he denigrates science and the facts it generates. All in all as a clinician, I deem our prognosis to be fair to good due to the dedication of scientists and our medical personnel.
Rich