I think EA believes that if they port the full game over, it'll probably not have a significant affect on raising sales. So they don't. All EA cares is if they can get as much money from FUT as possible. They could careless about that single player campaign.
2k on the other hand might think they have to port everything over to maximize profits. But I think the true reason everything is there is that the single player content, aka the hard stuff to port over, is connected to the microtransactions. So they want all that money. The rest of the game really doesn't change that much year to year. So they have to put in the effort to bring us the full experience to get those sweet, sweet microtransactions.