The Hardcore gamers purchase multipul games per month, per year. The casual purchase maybe 2-4 games per year. That in itself tells you the state that the Wii was in last generation. 

The Wii was a victim of this. The casuals bought up the Wii in droves, but did not purchase many games. = Developers did not see much of a return on their game develoment budget/profit. 

The Wii fateful also bought up their Wii's, but bought mostly 1st party exclusives, Mario/ Mario Kart/ Donkey Kong/ Kirby etc, but if you look at the 3rd party titles, again, the numbers were no way neir to what ps3/360 sales were, add to the fact that not many 3rd party titles made it to the Wii in any case, but still the sales were low. 

The WiiU is struggling because the casuals have yet to jump on (which they may not this time around), plus it seems like even the Big N faithful aernt buying the exclusive stuff (If they did you would see most 1st party titles selling more). 

The WiiU cant compete on 1st party titles alone, and by the looks of things, 3rd party support aint coming. 

Want to know why COD: Ghosts isnt in the WW charts?
Because It was not advertised. It was only announced about 2 weeks before release and the Wii U logo is not on any of the Ghosts trailers,
that and the fact that when it was announced it was uncertain if any DLC would be coming out for the system

3rd parties like Activision are screwing over the Nintendo console owners, so Nintendo console owners are returning the favour.

It's a temporary thing, because the data we have is from the second week of the PS4 (in the US) and the first week of the XBO (in select countries), with no notable third party Wii U games released in that week, and it's the week immediately before Black Friday.

If you look two weeks back, to before PS4 and XBO launches, CoD:Ghosts for Wii U was 41st. In the week before that, Sonic Lost World Wii U was 29th and AC4:BF Wii U was 41st. The week before that, LEGO Marvel Super Heroes Wii U was 22nd, Batman: Arkham Origins Wii U was 26th, and Skylanders Swap Force Wii U was 66th. The week before that, Skylanders Swap Force Wii U was 19th, Sonic Lost World Wii U was 52nd, and Just Dance 2014 Wii U was 65th. Going back a little more, we also see Rayman Legends, Disney Infinity, and Splinter Cell: Blacklist making it into the top 75 of at least one week.

Note that I'm not saying they're particularly strong numbers. Just that you can't judge it based on the last two weeks of data - they're special weeks. The real test is the next week of data, the week of Black Friday - specifically, the US numbers (European/Australian numbers won't spike until mid-December).

bolded: I guess that's why the wii sold less software than ps360, oh wait!

than the question is why did third parties support the vita but not wii u?

Xbox 360 is 50m off overtaking Wii software sales (excluding digital which are far higher on 360). With 20m less userbase.

I think it means Wii lost the buyers of 3rd party games to sony and ms.  Those buyers are brand loyal and won't come (back) to Nintendo without a real game changer.  btw, welcome back chris_wing!

exactly, wii owners bought lot's of games.

Lots of Nintendo games. 3rd party software didn't too well.