Basically, I see a worrying trend of Nintendo putting resources on Wii Fit, Wii Sports Club, Wii Party, Game and Wario, Wii Street, Wii Karaoke, while relegating the core development to remakes like WindWaker or direct sequels with reused assets, mechanics, design (NSMBU, DKC:TF, SM3DW). It's doubling down on the original Wii audience I don't think will pay off, while they slip further into irrelevance with the demos that actually spend their disposable income on, well, videogames.
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But those particular games have been in development for some time already. I doubt Nintendo would just cancel Wii Sports Club, Wii Party U, and Wii Fit U near the end of development because G&W bombed because they are probably (relatively) cheap to make and they will most likely profit from them. Now, if those games fail to sell well and Nintendo then continues to make these types of games, then I would agree Nintendo has a problem reading and responding to market trends.
Off Topic: I forgot Wii Party U was a thing. Kinda wish they'd just devoted resources to more Nintendo Land attractions, that game was like a Wii Party that actually worked.
Well, those are by 2 different development teams within 2 different development divisions. Additional Nintendo Land attractions would most likely come from EAD 2 (team Nintendo Land, Animal Crossing, and Wii Sports), while Wii Party is made from a division within SPD comprised of mostly former Hudson developers. So development of Wii Party does not preclude the possibility of NL DLC from being worked on.