No they aren't. If Splatoon was a complete game at launch with a season pass for future DLC then you could compare the two, as it stands the two concepts are nothing alike. I feel like I'm shouting at a wall at this point. Splatoon is a multiplayer-centric game launching with 5 maps, one mode, no voice chat, and no private matches. You have to wait for the rest of the content to be released. Buying an unfinished game at launch is not the same thing as purchasing a season pass to get future DLC for a finished game at launch You have not made a single reasonable argument that the two are even remotely comparable.
You're really missing it hard.
They are carving stuff out of Arkham Knight and selling it to you for $40 extra, and doing this a year ahead of release. Then unlocking the full game over time.
At least Splatoon isn't selling you part of a game for $60 and selling you the rest of it for $40. They're selling you an entire game that arrives in installments lol.
Here, I'll just quote this because you seem to be missing the forest for the trees.