There's a lot of reasons behind it I think as a complete history/politics deletant; damage from cold war anticommunism, side effect of post world war 2 success, and the general story the US and it's citizens tell about themselves as individualistic.
The US came out of WW2 immensely wealthy (overall of course not everyone was allowed to participate in the boom) which buried a lot of the impetus that pushed other European countries to create their national health systems.
Then we were fighting against communism which took so many forms of social programs into the area of forbidden ideology that could spell the doom of the US and the rest of the world.
And then there's just the individualistic streak that seems to have been endemic to the US since it's founding. Religiously as well as economically there's a lot of focus on individual effort and rewards.
The US came out of WW2 immensely wealthy (overall of course not everyone was allowed to participate in the boom) which buried a lot of the impetus that pushed other European countries to create their national health systems.
Then we were fighting against communism which took so many forms of social programs into the area of forbidden ideology that could spell the doom of the US and the rest of the world.
And then there's just the individualistic streak that seems to have been endemic to the US since it's founding. Religiously as well as economically there's a lot of focus on individual effort and rewards.