You would be surprised by the size of the share of the market Nintendo would have if they had at least a half decent relationship with third parties.

Well i left nintendo after n64 because off toon shading zelda, no gta3 and no dvd player on gamecube. Now im back because got bored off ps/xbox samey games.

Nintendo kept only their most dedicated fans. They were abandoned by non-gamers without much they could do and they abandoned the mainstream by having very small variety and 3rd party support.
there is nothing they can do this gen and I don't think they are willing to do for next gen. As that imply risk and possible loss, which we know Ninty is advert to.

The main problem i see is not Nintendos 1st Party its the total lack of 3rd Party.

Even on the Gamecube 3rd Party games were present and sold quite decently.

Actually the 1st /2nd Party is very good. Hell even Zombi U and Rayman/Deus Ex are good efforts but a lot of people are blinded by Playstation/Xbox now a days. Better graphics and no quality seems to be ok.. Just look how much of a mess AC Unity is and the lack of 1st Party Xbox/PS4 games...

The graphics on the Wii U are still better than the HD twins and i think for example Deus Ex/Rayman Legends are the ULTIMATE Versions!

What can Nintendo do?
1. more Advertising

2. TALK to 3d Parties get them back even if it costs a bit. no FIFA/AC and COD is killing the wii U no joke!

3. More games i think Nintendo are doing more collaborations.

4 This may be contriversial but get stuff like Turok/shadowman back ... How popular were games like Turok/Shadowman on the N64... Wernt a lot of Retro ex Turok devs ?

5. More Western Studios... At the moment most of the few games are Eastern centric... In the N64 days we had Rare maybe form a few new studios in the UK/US?

Nintendo has Hardcore Gamers, but generally only for their own products.

Core Games who also play third party titles however, are pretty rare, unless they prefer to play them on another console or a PC. And here we have a little bit of a self fufilling prophecy since gamers on Nintendo Systems buy Nintendo Games first, and third party games next, no matter what Nintendo console they own. Because of this, Nintendo generally only gets inferior ports with litte effort put in, which drives third party gamers even more to the other platforms. There's nothing Nintendo can do there unless they would slow the development of their own games to a crawl, basically forcing their audience to buy third party titles.

They tried exactly this with the Wii U, leaving third party developers the start of the consoles and Nintendo only to follow at a later date - and it failed miserably for different reasons (most games where already out on other systems and for a much cheaper pricetag, no evolution from the previous generation, no inclusion of previous titles of the series...), which sent the third party publishers away. This forced Nintendo to ramp up their Game development, leading to the droughts on Wii U games and the abandonement of the console by many potential customers.

Long story short, there is no real way Nintendo can win the third party developers because these already drove their own audience to the other systems. If they want core games, they have to either develop them theirselves or buy the rights from another developer (as done with Bayonetta and Devil's Third)

Well on the cube stuff like Resident Evil 4 sold excellently (and on the Wii too) yet no effort means no sales. Hells still angry about Capcom NOT bringing RE Remake or RE Revelations 2 to the Wii U. Sometimes i think 3rd Parties want Nintendo out of business......

Also Wii U has already outsold the Dreamcast, so I'm not sure what the OP is on about there.

Glad somebody else has noticed this.

Back in 2013 they literally flooded French TV with WiiU Party U & Wii Fit U commercials but the system flopped anyway. The casuals are gone, it's over.

Nintendo has an image problem. Also, lack of third party support. Of course right now Nintendo would be best off targeting the casual group.

Wrong, gc and n64 were some of the most powerfull systems at their times, the wiiu cant reach hardcore gamers dueto being the weakest system now