because fascists view art as the maintenance of aesthetic. to a fascist, art must inherently pursue and preserve a standard of 'beauty'. it feels nonsensical, but fascism is an ideology fundamentally centered around mythos and culture. An 'uncouth' or 'ugly' culture is 'd/generate', whereas a 'moral' and 'pretty' culture is 'pure'. fascists view art as the battlefield, because fascist analysis places the aesthetic at the level of importance that we place material conditions.

If they had paid enough attention in school to understand art can do more than deliver booba images, they wouldn't be fascists.

Genuinely, though, it's because fascism as a mass movement is currently in its transitory stage where it hasn't found a solid economic foothold. The American petit bourgeoisie is not anxious enough to really cause fascism to crystallize into a solid movement with a complete platform. This is useful for fascists because being vague and abstract allows them to appeal to more people who are just alienated enough to reject liberalism. Keeping everything down to just aesthetics in this ridiculously childish way is all they can do, which ends up working against them as well. I expect that if they had a more organized movement, the aesthetics would remain just as shallow and they still wouldn't understand art, but they'd be at the book burning stage so we'd have bigger problems at our hands than which side has better art.

Art is communication, communication facilitates understanding, idk quite how to articulate from C to D but that sounds dangerous for the fascist project

Also rejecting deviation means clamping down on personal expression, leaving just the one acceptable surface aesthetic

They're just being dishonest. They're okay with art that has a deeper meaning so long as the deeper meaning is also fascist.

Because they continually seek the moving (and impossible) target of some abstract and vague nostalgic perfect time.

They chase that dragon forever and anything new or provocative enrages them accordingly.

Because they're simple minded rubes