This explanation doesn't quite convince me, because if this really were the primary issue, USA could have globalized its consumer base not just for low quality products and pop culture, but high quality development.
I think the root problem is political: recognizing that USA's extraordinarily successful mid-century economic model was the result of a compromise by the ruling capitalists to avoid facing a European-style revolution (e.g. Bolshevism) at home.
As the Cold War reached its heights in the early 60s, that delicate equilibrium was destroyed, and the capitalists had a new mandate. State regulation, labor unions went from "necessary evil to avoid revolution" to "evil", and the robber barons could return to their early 20th century form. Thus we got the 70s and endless financialization.
I think the root problem is political: recognizing that USA's extraordinarily successful mid-century economic model was the result of a compromise by the ruling capitalists to avoid facing a European-style revolution (e.g. Bolshevism) at home.
As the Cold War reached its heights in the early 60s, that delicate equilibrium was destroyed, and the capitalists had a new mandate. State regulation, labor unions went from "necessary evil to avoid revolution" to "evil", and the robber barons could return to their early 20th century form. Thus we got the 70s and endless financialization.