The mechanics of how technology is built and marketed leads to the inevitable formation of walled garden ecosystems. When an entity is large enough, it becomes viable for other smaller entities to make money through their technical compatibility with the larger entity. The former is known as a "platform" and the latter an "app". The actions and policies of the platform determines what kinds of services, behaviors, and cross-platform compatibilities are easy, hard, or impossible to achieve.
Depending on the age and demeanor of the platform owners, particular platforms may achieve a reputation of being more "closed" or "open", based on the range of activities allowed on that platform. Both ends of the spectrum have their own advantages and business models, but they generally do not change very often. As a result, a platform opening up can be seen as a sign of weakness or capitulation. Such as today, when Nintendo surprise-announced a "business and capital alliance" with smartphone software developers DeNA.
Nintendo spent a lot of time reassuring everybody at the meeting that they weren't exiting the console business, to the point where they stealth-announced a "Codename NX" gaming platform. But it's painfully obvious to everyone that it's a desperation move. Nintendo spent four years or more actively denying any possibility of their games or branding ever appearing on a smartphone. They outright said that having their own hardware platforms was a strength, and it was a waste of talent to release their software on someone else's hardware.
Fast-forward to today, and Nintendo's CEO is now handwaving the question, saying that "it would be a waste not to use these devices", and comparing the decision to Nintendo's first big TV media buys. (That is, back when TV was invented. Nintendo is an old company.) The thing is, it was a waste not to use smartphones, all the way back when everybody and their dog moved to using them. Now, it's outright incompetence brought on by a management structure religiously invested in a particular set of competitive walls that don't really make sense anymore.
I'm just going to point out the last time Nintendo entered into this kind of arrangement with another company to expand to a new area of games, it was Nintendo and Phillips, and we wound up getting Hotel Mario out of the deal. DeNA's portfolio does not inspire confidence - they're a typical bog-standard cow clicker developer. I would have expected that if Nintendo wanted to make something on a smartphone, they'd figure out how to monetize or leverage it in a way that made sense for them. Not so much by partnering up with exactly the kind of developer that pumps out games that are shining examples of what Iwata would use to dismiss mobile devices as a new profit center to exploit.
Granted, Nintendo already published Pokemon Shuffle last month, which had me wondering why it wasn't on iOS. For a second, I had assumed Nintendo was trying to create their own parallel F2P space where they own the whole market. But it seems Nintendo is now suddently fine with the idea of making mobile games or software.
As a consumer, I personally think my 3DS is just a little bit too much for a casual game to live on. I keep it on my bag, but in order to play something on it, I have to take it out, boot up the app, wait for it to load, etc... whereas my smartphone is vastly more convenient and has better hardware to boot. Most other consumers don't even bother to take the 3DS, leaving it at home unless they're specifically with friends and want StreetPasses. It's just too bad that the battery life on phones sucks for gaming.