The reason I get queasy about the garages, despite your point about the district having a valid reason to build it for Disney, is that Universal built their garages without any public assistance when their expansion ambitions, and the expansion they had recently completed (City Walk and Islands of Adventure), necessitated it. Of course, their expansion was a boon to the surrounding area, and the garages served not only Universal directly, but also the CityWalk tenants.
Universal doesn't have a special district to pawn costs like this on to. They do get some good deals from the city and county, but they, as far as I know, paid for their garages out of pocket, despite a similar rationale for them (if not better) than the Disney Springs garages.