@alyx
Well, it is actually quite intuitive, why progresives believe this, when you watch Short fat otaku. Most "progessives" (Notice the name) believe in a linear progress of a society towards an inclusive globalist utopia. They believe, that all of human civilizations want to end up in that singular place, and only reactionaries are literally pulling breaks on this process.
Well, if you define progress in this linear way, then obviously someone with a nationalistic yet constructive view of society must have constructed their view on a past society. Because they are counter-progressive.
And yes, they are in fact morons.