I think first party platform holders are obviously more lenient about continuing franchises. I was just commenting on how people are celebrating this like it's a huge success. It's not. The game is doing well given the circumstances, but if this is the greatest success of the year for Nintendo, then it's a pretty shitty year!
I think many people here, me included, are surprised by the numbers it's pulling in Japan, both in absolute terms (new IP potentially selling 400-500k is not bad at all) and relative terms (it's on Wii U, better than Pikmin and Super Mario 3D World, better than other new successful new IPs such as Bloodborne). Also, sell-through signals an on-going interest for the game, which is good, since we're approaching Summer and the game might keep selling well until September.
I was curious, as well, to know which 2-3m new IPs (comparable to Splatoon) were shut down. Maybe Alan Wake? Pikmin 1 and 2 sold less than 2m worldwide (when Nintendo was in a stronger position) and a new entry was released in 2013, plus some remastered editions that sold quite well.