With the amount of games Nintendo makes and publishes every year for both consoles, it would mean that, in a world where they develop one game that works on all their platforms, there are no shortages from beginning to end of their lifecycle.
Telling a developer, that you will develop to na ecosystem instead of this or that console is more appealing from a financial point of view;
Buying exclusives means the risks of failing or lower;
Japanese developers (basically the ones that really support Nintendo) will develop for an even bigger audience and by releasing them, they would have a whole lot more to gain, too.
But that`s not all there is to it.
The real change comes from the use of the free staff and money they save on projects:
The extra money and staff could be used to develop genres Nintendo does not make;
Start their own mobile business and have staff that can focus only on that platform (porting it to the other platforms aswell);
Open more studios in the west;
