You shouldn't be too surprised to see that other games are developed in a way that makes it necessary to spend money in order to reach an aim. TSTO was money-hungry too, and once or twice a year I bought some donuts. But then they gave us the ability to build donuts on our own. And I think, that is one of the things that killed the game.
Don't forget that servers are huge and expensive, and they need a lot of space and electricity (which is also a problem for the environment). Don't be surprised that game makers have to make sure that the games make a profit. Companies like ea are not social enterprises. You work commercially.
And as I read at a another place, it's also a question of ending licences for using the characters of the Simpsons.
Don't misunderstand me. I love the game, and I'm so sad about its near end that I almost can't bring myself to entering the game since I know that the end is near. I will miss it.