With Reedy Creek, Disney doesn't need to worry about whether local politicians will approve expansions or meet the needs of the Walt Disney World complex since the local government is purely serving Disney.
If you take a look at Disneyland in California, Disney is going up against Anaheim and Orange County councils on a pretty routine basis to get new things built.
Sure it's a benefit to Disney, but it's also a benefit to the county taxpayers:
* Disney subsidizes both counties' services and infrastructure by paying property taxes to pay for services/infrastructure, but not consuming them, or contracting for them where needed.
* Allows counties to avoid costly legal and procedural issues when Disney wants to add new features, attractions, or services at their park, or wish to ensure consistency of services provided by the two different counties.
So, what is the crux of your objection?