That was Disney's plan prior to Michael Eisner... He was too much of a control freak to let them do it and it was resolved through some pretty nasty litigation with Tishman that resulted in the Swan & Dolphin...
Early Hours are a potential perk, but I think particularly at WDW it has more to do with the notion that 1990s amenities aren't what modern audiences are looking for today. And Disney isn't willing to reinvest in the hard product enough to offer something compelling. They likely have run the numbers and find the ROI isn't there. They're also stuck with a strong fan community... Take the contemporary resort... In my view, the main building should be demolished... It is dated, ugly, and hardly revolutionary anymore... But just imagine what would happen if Josh D'Amaro got up there and said they were tearing that thing down to build the new Disney's Frozen Resort in its place!