I want to add: DisneylandForward was necessary for Disney to further develop the DLR, and required community support plus city council approval. It replaced an agreement signed on the dying days of WestCot - that agreement was reached after a bitter response and protest from Anaheim residents. (Of course, Anaheim is a much different place today and few of those residents still live there.)
But in my lifetime, think of all the cancelled projects that were announced… a full buildout of Toontown based on Roger Rabbit. A new land based on Hollywood featuring The Great Moviie Ride and attractions based on the Muppets. WestCot abd PortDisney. DCA 2.0 downsizing, featuring the loss of a second dark ride. Initial Avengers Canpus attractions. Redevelopment of Innovariojs/ Autopia/ Submarine Voyage/ the defunct water Autopia.
The list goes on… same thing at WDW. They cut the budget of Animal Kingdom so badly, that many of the people that joined Disney from San Diego Zoo and elsewhere left. Heck, the Imagineers that designed one of the headlining attractions in Beaslty Kingdom (cancelled) left to build at similar attraction at Islands of Adventure.