As long as there is somewhere like Playstation/Xbox that let third parties sell big numbers, they will not go back to Nintendo. The last time third parties sold well on a Nintendo platform was during SNES when Capcom, Square and Enix managed to get on top 20 list of best selling games. Since then Nintendo hadware sells Nintendo software. A few exceptions like Monster Hunter and Yokai Watch on handhelds does not alter the fact that people that invest in Nintendo mostly are interested in Nintendo software.
Go to the VGChartz database and look at the 20 top sellers on Nintendo systems. All the time since NES and Gameboy the Nintendo games have a massive presence. This is not the case for Playstation and Xbox, where third parties sell better than platform exclusives. Sega used to have the same situation as Nintendo with their consoles, selling mostly Sega games.
