I'm guessing that the games will only be available for a limited period of time, then if you still want to play them you'll have to purchase them, which would be very different from Netflix.
I doubt these games have any of the DLC. You might be able to purchase the DLC, but then when the game is no longer offered on the service you'll be left with worthless DLC until you buy the full game.
Some people also purchase all services of this type, even if they already have the full games, because it's also offering exclusive content and betas, so it's basically a free $30 for each of those people to EA, millions of people times $30.