Honestly the extra magic hours is a plus to stay on property.
Disneyland is based on where you stay OR the number of days on your ticket. I would think that Epcot would be more economical to add the hours at the end since the whole land area doesn't open till 11. Most is for shopping and that's money in their pocket, but also more people to pay. It all comes down to money and making as much as they can to cover the cost of the new Tokyo that was over budget and not bringing people in. If they have to staff the whole park, not just the rides, people are usually not eating a lot at that time of night, and the crowds don't sustain the park, its hard to justify the cost. Don't get me wrong. I love the extra hours and I use them, but I can also see the business side of things.