Im going to cry into my copy of Xenoblade Chronicles X because of this news, also we now know Guitar hero isnt the Tantalus port hoooray.

Nintendo needs to do something if this trend continues for 3rd party.

I think they're in for a surprise if they think Rock Band 4 will do very well on PS4 and One; fringe customers are gone from home consoles, there is no sense chasing this demographic in this sphere any longer and they'd be better of making games for mobile devices.

I find it amazing how third parties these days are unprofessional enough to skip wii u AND offend the fanbase with lies like this. There are times when keeping quiet is better than saying any random BS and this was one of those times for them.

Theres really no evidence of this If by fringe you mean the casual console audience that buy only 1-3 games per year. If however you mean the audience nintendo brought in with the blue ocean startegy  of wii sports, wii fit and brain training they're not the heart of the rock band userbase. The rock band audience has been around from PS2 days and cannot easily be defined by demographic. 

Rockband =/= Just Dance

Rockband will sell most of its units on whatever systems are considered mainstream and accessible at the time, its not so simple as casual/core. It missing PS3/360 (even in spite of declining software) is more confusing then missing Wii U, but I'm grateful for it being next gen exclusive tbh. Will push neccessary hardware.

Also they said that they're making the game on the most restrictive budget yet which I guess explains the focus on PS4/X1, both of which will be the focus off holiday spending when this game is released later this year. I presume a Wii U version would be on the mix if they're weren't being so conservative with their cash, maybe after they've made their money back from the PS4/X1 versions it'd come to Wii U.

It isn't. Not that it matters on the subject of rock band. I was just saying.

Depends what you mean by casual market, did the 360 have it? (prior to kinect)

Because Rockband sold best on that platform from an initial look. 

User base between Xbox one and Wii u is just 2-3 million apart. So hardly a big gap.
Demographic wise this type of game won't sell that much on its first week. This game is meant to play local coop with plastic instruments so it is an expensive game.

I have friends who bought this game on the wii with all the instruments of course crazy to buy this game without those anyway. For the Xbox and ps owners they didn't even try to buy this game. In not saying it is the Trend to all but there is a user base for a particular genre/game.
Still not a big lose but if the development was similar with pa and Xbox they surely have thought to build it for the wii u too.

If they want the crowd, hope they can have those old plastic instruments(PS3/xbox360) run on ps4 and Xbox one. Game would sell better.

That's why I call them fringe and not casual customers, these are the inbetween customers that buy more games than casuals but less than hardcore, the ones who buy simpler fare from time to time to get a break from bigger games and perhaps have fun with friends. The ones who got hooked on wordfeud and similar, competitive games like Quiz Battle on mobile devices, all the while still buying every odd console or PC game as well, and the same that made up the chunk of the user base for games like Buzz, Singstar and Rock Band. Of course, the majority of Quiz Battle and wordfeud gamers don't care much for regular games. Look at Nintendo's Brain Training games for another good example of how these customers have changed habbits.

Fringe customers are neither here nor there but there are better, not to mention a whole lot cheaper, alternatives now on mobile devices and perceived value rules the day. It's not like Rock Band is cheap with all the instruments anyway. This is also why Wii Fit U was a horrible idea despite the success of the first two games; there are now better and miles cheaper alternatives on mobile devices. This is probably the biggest indicator we have right now of what these customers are doing, while Wii Fit and Wii Fit Plus had well over 20% attach rate; Wii Fit U has slightly more than 5% at this point, this figure will shrink as the lifetime sales of the console increase (likely ending up around 2.5-3% when all is said and done).

Developers are still dealing with how they go about catering to a splintered market and these changes are still fairly recent. Expect a lot of games to fall on their asses before things change much.

I could be wrong, who knows? I guess the sales of Rock Band 4 will tell at any rate.