I agree that consideration is probably the weakest argument but not for the reasons the attorneys you spoke with think.
As others have suggested, the implied consideration for development contracts is to improve land in order to increase tax revenue. Arguably, this is the primary reason for development contracts.
The actual wording in the development contract is:
Provision of Necessary Public Facilities. In order to facilitate the implementation of and provide adequate levels of service for the Maximum Development Program, certain public infrastructure systems will require new facilities and/or expansions of existing facilities (hereinafter referred to as the "Public Facilities"). The Public Facilities are listed in the Capital Improvement Element of the Comprehensive Plan a copy of which is attached hereto and incorporated herein as EXHIBIT 3, and will be funded, designed and constructed or cause to be constructed by RCID. Any land required for the Public Facilities that is owned by Master Developer shall be dedicated to RCID, or other public entity, as required. Compensation for said land dedication shall be negotiated between parties at the time of transfer but in no event shall Master Developer request payment for the land in excess of fair market value as determined by a Member of the Appraisal Institute (MAI) real estate appraiser, jointly selected by the Parties.
This is garbage.
Disney is saying in effect, "If we build something and it requires a new road, bridge, sewer, etc. to support it, you RCID must pay for it but, hey, we're gonna sell you the land you need to build this at fair market value."
This is no consideration at all!
If the district attempted to take more than the "land required", Disney would certainly fight them in court.
If the district refused to build this infrastructure, Disney would take them to court.
If the district, for example, tried to take control of the entrance into the Magic Kingdom by eminent domain, Disney most assuredly would fight it.
Disney has given the district
nothing, other than "permission" to pay for and build infrastructure Disney needs for projects that Disney decides to build.
Again, the true consideration is increased tax revenue from land improvement.