First, we don’t know the full terms of their agreement, so a lot of this is based on my own knowledge, which is limited, but Nintendo simply could make more money, in the long run, if it built and designed its own theme parks. Walt Disney Productions always had money problemsduring Walt’s lifetime, but only Disneyland solved that. A Nintendo park would help insulate Nintendo’s financial performance and allow for novel creative opportunities for their characters/worlds and for their creators to experiment in the medium of themed entertainment.
Second, Nintendo is a very controlling company that knows exactly what it wants. The problem is that they have no internal competency to actually build and operate a theme park.
My suspicion about the initial UNI deal was that they had looked into building their own park with a partner, possibly OLC, and they came to the conclusion that they weren’t in a position to succeed at it at that point in time. With UNI they could get a high quality Nintendo land for Tokyo 2020 and start to slowly accumulate knowledge to build their own park(s), eventually. But having UNI build a new gate in FL with their IP as a central component versus what’s being done in Osaka and LA will present challenges in bringing their own parks to market in North America and Japan.
It’s honestly worst than the Marvel deal for them.
PS: To this day, the parks are still Disney’s cash machine. Just in case you were wondering who’s going to pay for the Fox deal.