It's interesting that no one seems to be arguing that Nintendo's decades-long commitment to Pokemon is what helped spur this success.
Look, Ingress and Niantic and Google all certainly played their role.
But Pokemon doesn't exist without Nintendo.
The core gameplay mechanics of gyms, of the 151, of different types of Pokemon and Pokeballs, of eggs. Think about the names of Pokemon we love. Think about their designs. Think about the sounds and music that we recognize.
None of this exists without generations of Game Freak and Nintendo polishing mechanics. And this is just what we KNOW Nintendo influenced. Who knows what differences between PoGo and Ingress are because of Nintendo's mentorship. Yeah, it probably made for a simpler game - but look at Splatoon for how Nintendo can take a complex premise/genre and use a different take on it to simplify and make it accessible.
Nintendo has a history of flirting with and working with other developers. Is Sm4sh all of a sudden Namco's game because a huge portion of the Dev team was theirs?
No.
PoGo is a collaboration. Some products are, particularly with modern Nintendo (see Sm4sh, Pokken Tournament, tons of smaller 3DS games).
It's just funny that even with the fastest selling game in the history of smartphones... and even with moral and responsible monitization in the f2p space (which so many great devs from Ubi to EA get wrong) people are still dismissing Nintendo's role in this game.
Even if Niantic did the whole thing. Pokemon isn't just "IP." It's a whole fucking system of gameplay mechanics and tropes that we've become familiar with and enjoyed for TWO DECADES.
That doesn't happen by chance. Everyone involved deserves kudos with this one. Nintendo included (and maybe even most of all, as were seeing).