As long as Nintendo refuses to elevate 3rd party titles to the same level as theirs and promote them equally, they will continue to suffer poor 3rd party support, and 3rd parties will rightly be biased against them. And anyone who says Nintendo games like DK Tropical Freeze, MK 8 and Mario 3D World for example are above and beyond top 3rd party AAA titles, well, that's a perfect example of why Nintendo's console sales are in the crapper these days and why 3rd parties ignore Nintendo.
That wont happen until third parties start treating Nintendo equally. You talked about bundles, well, Nintendo had a ZombiU bundle at launch, but what other big third party games deserved bundles? Watch Dogs? Nintendo isn't going to say "get your sub par multiplats late, only on Wii U!"...thats just silly. Nintendo can't work with something that isn't there...
PS: It isn't Nintendo's job to promote third party games...that what the publisher is for. However, I would like to point out that there are some third party games that Nintendo has published in the west such as Monster Hunter