I'm not sure about the "new reformed Major Disaster". I liked the old classic bad guy who could cause earthquakes, shoot lightning from his hands, and stuff like that. That's the one I'd like to see.
I thought about Major Disaster overnight and I realized that what Major Disaster's major flaw was that he was a Marvel character in a DC universe.
With his powersets of earthquake generation and lightning control (and possibly other powers like storm control and fireball generation, the Wiki entries seem to be a bit vague on the subject and only discuss his current incarnation), he sounds like someone who (with proper training) could go toe-to-toe in a proper slobberknocker with someone like Thor or Iron Man. Yet he was created in the DC universe where Julie Schwartz and his writers probably didn't watch too much wrestling and so involved him in clever puzzlers with the Flash and Green Lantern. Going up against Flash and Green Lantern (two of the cleverest super-heroes around, especially as handled by Julie Schwartz, Gardner Fox and John Broome) would make any villain look like a putz. Thus his mortyrdom in later years to be regarded as a candidate for the the Giffen/DeMatteis Justice League stories.
What he needed was some serious Stan Lee monologues, declaring how great and powerful he was and how he could completely destroy Green Lantern and the Flash and whoever stepped in his way, blah blah blah. Add some potent displays of power and he could've been an Amazo-level villain capable of taking on the entire Justice League (in a non-Giffen/DeMatteis manner).
Turning him into a megalomaniacal Marvel character might've made more sense than turning, say, Despero into one (truly, a brainy villain if there was one, dumbed down in later years to be an evil smart Hulk) or even Starro, especially in his recently-previewed new incarnation.