Arguably it is the wrong strategy, especially if the unspoken possibility of war with China becomes a spoken one. The USA has an edge in raw technological prowess. The F-35 plays to that strength, with tons of advanced technology that took a long time to master and develop. Setting up factories that can churn out cheap planes en-masse is certainly possible and if the USA found itself in a war of attrition it'd probably do that surprisingly fast. But why get into such a situation, in which the US would have no real advantage and perhaps some disadvantages, when it can compete on pure tech and build one plane that can take out many of the opponents cheap planes?