Deep lore actually already explained why Palpatine wasn’t that bad. In the Star Wars EU (before it got nuked by Disney) he was actually building the Death Stars as a way to prepare for super powerful invaders that would be coming from a different galaxy.
So, yeah, this wouldn’t work on them.
Come now comrade, I didn’t expect to find revisionist Sith propaganda on my favourite trainposting forum.
Palpatine was absolutely that bad. He wasn’t building the Empire because he wanted to save the galaxy from the Yuuzhan Vong. He was a megalomaniac sadist who believed he was the living embodiement of the Dark Side of the force and wanted to turn the galaxy into a hellscape where dark side users ruled supreme and the dark side of the force was the only power worth having. He even wanted to eventually destroy most of the tech in the galaxy to make sure dark side users couldn’t be challenged by normies with cool toys.
Palpatine never really gave that much of a shit about the Yuuzhan Vong, that was just a lie he told to get Thrawn to kill Jedi for him and Thrawn believed Palpatine because Thrawn, his writers, and a disturbing amount of his fans are the sort of fashy fucks who like to jerk off to the idea of a genius general “unifying” the galaxy under a horrific tyrant to save it from being conquered by a rapist coded outside threat.
The Yuuzhan Vong were intergalactic Nomads. They didn’t have any planets so the Death Star, whose main feature was a laser used for vaporising planets, clearly wasn’t built to combat them. If he was actually worried about the Vong he’d have used those resources to build experimental anti-biotech weapons or just more Star Destroyers.
The Death Star was a terror weapon that was there to destroy any world that dared rebel against the increasingly horrific shit Palpatine was planning to plunge the galaxy into. They literally spell it out in ANH when Tarkin says “Fear will keep the local systems in line. Fear of this battlestation.”
There’s even some cool kinda lefty stuff in the EU where they explicitly associate the Tarkin doctrine with the War on Terror by having Palpatine go on space Ellen and say he was sad about blowing up Alderaan but he had to do it because they were terrorists stockpiling weapons of mass destruction.
There’s enough material in the Star Wars EU that you can read pretty much anything into it, but to justify a “Palpatine did the Empire to stop the Vong” take you have to ignore that Palpatine was planning to take as much power as he possibly could from the time he was a small child, started the clone wars despite already knowing the Vong were infiltrating the galactic rim, that once Palpatine seized power he poured significant portions of his Empire’s massive industrial power into manufacturing planet killers which would be useless against the Vong, that he wasted entire fleets trying to cultivate dark side masters who would be far less effective against the Vong than those fleets, and eventually planned on dismantling the Empire’s tech and replacing it with dark side users who the Vong are naturally resistant too, while believing fascist rhetoric which is explicitly stated in universe to be manipulative lies.
Palpatine’s personal immorality, explicitly fascist goals, assault on the republic’s “liberal democracy” and obvious personal sadism and megalomania means there isn’t really a liberal “palpatine did nothing wrong” take. You have to be coming from a “contrarian” proto/crypto/fullblown fash position.
The lib take is that the slaver empire known as the “Galactic Republic” and their child abusing mind raping theocratic enforcers the “Jedi Order” are cool and good.
The only true lefitist take on the Star Wars universe is of course to advocate for solidarity between the enslaved droid and organic proletariats and agitate for an immediate and protracted pan-Galactic peoples war against their bourgeois oppressors and the Bio-Supremacist force “gods” who enable them.
Best Star Wars take I’ve seen in a while, well done. Even if the ‘Palps wanted to save the galaxy from the Yuuzhan Vong’ take could technically be correct (clearly isn’t for reasons you outlined), he absolutely and monstrously committed far far worse attrocities in his “preparations” than the Vong ever really did themselves. And clearly desired to continue those activities well after they were gone (re: all his immortality/bodysnatching attempts when the Vong were literally just 30 years away).
And even then, if somehow he weighed the odds and figured “nah this whole beat a rock with a pair of scissors start is way way better than just raising an absolute fuckload of clones and droids and deploying them directly in defense of the galaxy”, he was still so absolutely wrong that he lost his Empire to a much less powerful force and made the galaxy less stable and capable of fending off an attack than before his reign.
And even in the absolute dumbass take of “he knew everything that would happen so he had to do all the bad so Luke would do good and be strong enough to win” he still fucked that up so royally he made the Emperor of Mankind and the God Emperor both look extremely competant at grooming subordinates to manage their empires and deal with threats.