The site's reasoning is that the iPhone owns the casual gaming audience, and with a proper controller, it can claim the hardcore sector of the market, too.
On paper, the figures seem solid — there are around 125 million "mobile gamers" compared to 35 million 3DS owners and the mobile market is worth a lot more in terms of revenue, too. However, such a prediction fails to note that physical controllers on smartphones aren't a new concept — Android has seen several examples already, and the iCade "arcade-style" gaming unit already supports iOS.
The Fool also ignores the fact that Sony's attempt to make a gaming phone, the Xperia Play — surely the one thing that could have destroyed Nintendo's market share — failed to strike a chord with players.
Physical controls on smartphones are all well and good, and will unquestionably lead to better games — we've already seen that with the Nvidia Shield Android-based handheld — but most mobile players don't want to have to carry around a separate controller with them.
The beauty of smartphone gaming is arguably its simplicity; you have your phone on you at all times, so it's easy to pull it out for a quick game — a snack between "proper" gaming sessions which won't ruin your appetite for more complex titles on dedicated handhelds and home consoles.
Android bolt-on control pads have been around for years and have so far struggled to make a massive impact, and there are more Android devices out there than iOS ones — proving the Fool's prediction false.
At the end of the day, mobile and handheld gaming are two very different beasts, and we're pretty confident that it will take a lot more than an external controller to kill Nintendo's business. What are your thoughts?