The realism is brilliant IMO, and I fail to see how it can be construed as a negative thing given that Disney World had a lot of realistic aesthetics particularly in the 70's and 80's. Though there's still clearly some more fantastical elements in the form of the Tree of Life's magnificent sculptures (IMHO an absolute triumph of Disney craftsmanship. It was awesome to see a park that wasn't overtly toonified as late as 1998.
I also seriously doubt he's ever seen himself as exploitative by "exoticizing poverty" as you say. I don't see that myself. Even if you entertain such an argument, he's far from the only imagineer at Disney to romanticize or even poke harmless fun at cultural trends and/or common cliches of older time periods. Pirates of the Caribbean being a good example of an original Walt Disney attraction, which a couple of oddballs who are far too sensitive and upset about regarding the manner in which pirates are portrayed (and particularly their treatment of women). Same goes for Frontierland, and the way it romanticizes that era while ignoring all the injustice of slavery occurring during all those periods of time, or the horrible violence and injustice inflicted upon Indians/NativeAmericans. And if you want to get really overly PC about this, Haunted Mansion could be said to "trivialize" death.
There are a lot of negative historical events glossed over or poked fun at in EPCOT rides as well. Spaceship Earth is all about our amazing accomplishments in history (formerly our advancement in communication tech), and it conveniently skips the more horrible historical events in favor of a more idealistic view of humanity and our future. World of Motion was a somewhat lighthearted ride with goofy interpretations of (otherwise negative) events such as a large vehicle crash and a train robbery. Not to mention that pretty much all the countries at World Showcase have had horrible events in their history that are better left not focused on in a Disney park.