Nintendo really needs to expand. Right now they're kind of stuck in a niche, and I don't know if they're brave enough to go outside of it.Well they have finally figured out some other revenue streams recently - they are leveraging their IPs (that rival Disney in ubiquitousness) to mobile games (DeNA), toy figures (amiibos), and to Universal for attraction parks. Why they haven't done this before is mind boggling.
The real problem Nintendo is trying to solve is software production - they have a hard time right now developing titles for their handheld and consoles at the same time. So usually you get one year full of 3DS titles and the next is full of console titles - this year's E3 was almost entirely new 3DS games for example. While they release more first or 2nd party titles a year than any developer, it's still not enough to support their own hardware completely - which is why the lack of 3rd party support hurts so much.
They are taking steps to solve that. They recently merged their handheld and console development teams into the same building, and for their next generation of handheld/console (if the NX isn't both in one device) they are planning for it's OS to be completely scalable so that they can more easily develop games for both. Basically they are doubling down on supporting their hardware single-handedly without 3rd parties.
They need to realize that a lot of gamers are in their 20s and 30s now. And while a lot of us do like Mario, Zelda, etc, we also want some new shit. Splatoon is neat, but they need some things to appeal to older gamers as well.