When you are at a theme park everything is taken care of for you. You don't have to worry about the details of how the park is run. The only difficult part about being in a theme park is picking which ride to get on.
Having a theme park experience at a development organization means developers can focus on delivering features and not on repetitive tasks, red tape, or figuring why it's broken in dev but it works on my machine.
When developers are free to focus on solving problems, not only are they more efficient, but they are more satisfied with what they are doing and as a result: happier.