There is a reason why games like FIFA are lambasted on Nintendo systems...because they dont have all the new features the other systems have, each year. Starting from that point, it is entirely contradictory to say that those games are the same or with very little change between each version. If that was the case the Nintendo system editions would actually be par with every other console.
The thing is, those game are most of the time quite well made. They introduce good and new features that the people who play them enjoy and want, and you are sorely underestimating their fanbase if you believe they would not recognize a new release from an old one if their titles were hidden or something like that. Same with Pokemon and Animal crossing, for many people they seem to be always more of the same, but for the core fanbase they are not. I for one have as much interest in thew AC as in the yearly FIFA release, but I still know the games are good and extremely popular for what they are and with good reason.