Honestly, Nintendo's decisions have been questionable going all the way back to the Super Nintendo, where they steered hard away from "adult" material like blood and violence. Since the growth of the VG market was mostly among teens and young adults, that meant Nintendo was starting from a position of weakness all the way back in the mid 90s. It only got worse from there. The N64 insisted on using cartridges and had that god-awful controller. And the gamecube was a joke. And all the while, third party support was dropping off.
And yes, the constant stream of Mario, Zelda, and Pokemon games is not doing Nintendo any favors. They've been alienating third party developers for years, and they don't seem to care that their game library is quickly becoming an inbred mess of iconic characters from 25 years ago.
I wish they would focus seriously on developing some new IPs.