Completely agree, I’ve always had an issue with how Hades is portrayed, mainly because as you pointed out, his motivation makes no sense.
“Oh yeah, I’ll just destroy the majority of the planet to experiment with a power that I should already have complete mastery of, because I’m a god. That makes sense.” It also destroys any potential character that Acheron might have, since all his decision can be chalked up to the voices Hades told me to do it. I’m all in favor of puppet master/manipulator characters, I mean my main antagonist that I made for my AO fanfic is very much a puppet master, but it’s not a complete control of other’s actions.
The best antagonist like that are the ones who can cause events to fall in their favor without their victims even knowing ala The Count of Monte Cristo (who I know is the protagonist, but it still works). Hades fails in this regard because he’s directly influencing/controlling (the LD is unclear) Acheron through a corrupting force, a force which Acheron never gets a chance to be free from again weakening his character and presence as a major villain in AO history.
Over all Hades is just a weak character, and while he could totally be a great antagonist as I’ve written about before, but he needs to be more than a generic dark lord type, and actually given some presence within the story beyond the last paragraph of the Lore Doc.