Cyrus on 23 October 2014
I think because the casual market has significantly changed.
Last gen the wii introduced motion play that was easy to adapt for everyone and made the wii lead despite of being less powerful than their competitors.
This gen the WiiU doesn't have a lot to offer for the casuals, it's just core gaming.
So the only points for casuals to search their system this gen is power and amount of advertisement.
Since xbox1 and ps4 have more third party, they naturally also receive more advertisement. So people just go for the ps4 because its cheaper than xbox1 + more powerful.
While the smaller group of core gamers goes with nintendo.
