Hollywood reporter takes a stab at explaining why.
TLDR: It was a story about a gay child. A focus group was shown the movie and unanimously said they would not go to theaters to see it. Studio execs wanted changes and fought with the director. They fired him. New guy was brought in, they tried to shoehorn in a different story. Article writer wonders if the movie would have made money if the execs just left it alone. Yes, it would have made billions. People have been dying to see an animated movie about a gay child.
