It was always pretty obvious to me that the Ascians and Garleans would be fleshed out over time and given a sympathetic backstory given that...pretty much every JRPG I can think of has done just that with its own antagonists, including a lot of the Final Fantasy titles...

Furthermore, Hydaelyn was always portrayed as being evasive and shady. It just so happens that anyone who pointed that out was harassed, especially on the lore forum! Coincidentally a place infested with 'mOmMy StEpPy' types even before Shadowbringers.

It's also being ignored that many Garlean and Ascian fans repeatedly spoke up in favour of more nuance and less cackling villainy only to be shot down (ironically by some of those now lamenting the lack of nuance back in the days of ARR). Such individuals also had a habit of pushing for a 'third way forward' that allowed all factions to come to some form of mutually beneficial compromise. Which wouldn't have been difficult to create if the writers are already prepared to conjure up entire alternate realities to justify the continued existence of burger boy.

Furthermore, the Final Days happened because a nutty subversive individual in the form of Venat stood by and allowed them to happen. With that in mind, pretending as if Zodiark was a bad decision is - quite frankly - bizarre given that Etheirys only persisted as a consequence of Zodiark being summoned to fix the mess caused by Hermes and Venat...