I don't remember Kirby and Mario Party 10 getting the same treatment, but if you say so.

In all fairness Kirby and the Canvas curse on DS only sold 720K accoridng to vgchartz on the DS's userbase, so the 150K on Wii U isn't horrible honestly.

I do think Splatoon will do fairly well, the reviews have been pretty positive, people generally enjoyed the testfire demos a lot and Nintendo is pushing the marketing pretty hard. And at a few of the local EB Games here they actually had Splatoon posters covering the outside windows! Nintendo never gets that kind of advertising from there here.

My simple answer to your question is that exactly what you say, I feel the same about every other shooter released. They're mostly new map packs with a few different weapons and menus. Splatoon is a fresh take on the genre and stays inline with what Nintendo fans often crave: colors, originality, fun, and of course a new fricking game, period. Don't forget that this is our first major release of this year.

Every Nintendo exclusive? You mean like Codename STEAM? What about Kirby & The Rainbow Curse? Mario vs Donkey Kong: Tipping Stars? Rodea The Sky Soldier? Devil's Third?

Please. Stop with your generalizations.

Bayonnetta and that toad game did. 

Hm, I wonder why that is?

Oh wait, they were extremely polished and enjoyable games. That's right.

Allow me to quote you. 

1. first good game on wii u this year outside japan
2. Incredibly fun, completly new and innovative gameplay
3. Fits wii u community perfectly in terms of graphics, artstyle and gameplay
4. Testfire demo was a big sucsess, almost only very positive feedback
5. Nintendo is doing alot marketing

the testfire was fuckn awesome!

This baffles me too, I would have assumed many people here would be mad about the lack of voice chat and dlc method of release. Honestly, I do not think it will do well at all, and that people here are overestimating, but I could be wrong