If it's like any other large suburb, the people who run Anaheim are only there short term as a springboard to bigger offices. If you want to move up in politics, Disney is a great friend with deep pockets. So they probably did the bare minimum of analysis with the goal of giving Disney what they wanted.

Edit: Wanted to add that this is actually a great way to think about people's motivations. Most people are not stupid; so assume a smart person made this seemingly stupid decision. If you do that, you can usually back into their personal motivations, which probably are not aligned with those of the organization they are representing.