I get why Europeans might analyze it like this but itโs not so simple.
In n out is Californian. California was a red state. States change and evolve.
And the premise is kinda false too, literally. Conservative institutions are alive and well.
(Imagined) European validation of American low culture is like crack cocaine to them, it seems. At first, I found it baffling how Red Americans actually seem to feel nationalistic pride of hamburgers, gas stations and cars rather than their national heroes, achievements etc...