For now, I think this concept was an exception. Nintendo and the young developers really wanted this new IP to not only sell well, but gain continued interest. Considering the genre it would be competing in, Splatoon had to stand out. It now has legs that almost matches the likes of Mario Kart. I think if we got a majority of all of the content we have now at launch, Nintendo's young developers thought they would risk having casual players lose interest or be overwhelmed.
I mean think about the Wii U's install base. If one wanted to play Tower Control but everyone else wanted to play Turf Wars or something else, then the mode would be barren.. Splatoon doesn't have the prestige to ensure a good amount of sales. At least here, with constant stream of updates, everyone has a fair chance of seeing what's coming up next and be on a more even playing field. Sure, the game was bare bones in the beginning, but I think the young team wanted to play the long game. It was a ballsy move, but it created constant interest throughout the year. As for the potential sequel, I think it will not have the same concept in terms of content updates as the audience is now established and Splatoon is well recognized. Plus, it's got to be a bigger game.







