All the absolutes in here make it very hard to get on board. Americans are not Marxist automatons any more than American culture is something so well-defined that you can reason about it reliably with generalizations like this.

I'm not a cultural anthropologist, so I'm not going to bother suggesting this Marxist origin theory is wrong or even not a large contributor, but I will certainly point out that you're reducing something very large and very complex involving a whole lot of vastly different people with different motivations, backgrounds, and goals to a simple, homogeneous, no-moving-parts summary that's so burdened with subjective assumptions as to be unsupportable.