There's truth in that, by it's slightly different. People can pick both PS4 & PSV versions to be able to play and get trophies anywhere, while still having the best version on big screen. 

Got to lead from the front Nintendo.

I believe I've read identical statements like these from Nintendo since Gamecube.

I think a lot of devs are going to be looking at how well Skyrim and Doom sell to assess whether they should invest in bringing mature titles to Switch.

This scares me.

If you're worried, you could always do your bit and vote with your wallet. :P

Number of nintendo fans in this thread excited at the possibility of mature games being ported to switch: lots
Number of Sony/Microsoft fans in this thread excited at the possibility of switching their main console to the switch: none.

Nintendo, do it for your fanbase, don't do it trying to take a bite out of other pies, just make your own pie more delicious for your current customers.

Wall Street Journal said this? The same people who fabricated the rumor that Nintendo is planning to ship 20 million Switch units this fiscal year?

Good move. They earned the family friendly rep and it's going to be theirs for awhile to come no matter what. Good to get broad appeal and still keep the family image.

To create an audience.

If Nintendo was to show that M-Rated titles can succeed, it's on them to develop, market, and publish a slew of M-Rated titles. Mario and Zelda, are fantastic,

(played a little of BOTW and it's amazing and Odyssey is looking killer), but they don't seed a market for Grand Theft Auto, and Call of Duty. We saw what happened with the WiiU. It just doesn't work.

That's not how to make an audience on a fledgling platform. Third party developers and publishers are in the business of exploiting audiences, not creating them. They see poor sales, and then they pull out. If Nintendo did the same (make M-rated games in genres that gamers want, like shooters), they would probably see poor sales too. The difference is perspective: Nintendo sees an audience growing, and third party developers will see it as an unwise investment, compared to spending the same amount of money on PS4/XB1/PC titles. If Nintendo intends to break ground, they need a big  M-rated flagship title with that usual Nintendo polish. If Nintendo fails to lead the way, M-Rated games on Switch could go the same route Wii U did

TL;DR It's up to Nintendo to make an audience. If initial sales of big M-rated ports do poorly, M-Rated games on Nintendo consoles goes the way of Wii U