Essentially yes(in my opinion). Even if the NX has half the third party support that the PS4 does(which I doubt), most Nintendo fans don't buy third party games for Nintendo consoles AND most people that are into major third party games(COD, Assassin's Creed, Madden, Fifa, Far Cry, GTA, Battlefield, Deus Ex, Hitman etc) aren't really into Nintendo games.
This year is going to be killer for the PS4 even just factoring in it's exclusives. I can count at least 9 console exclusives for PS4 for this year(including Street Fighter V). Continued strong sales and heavy hitters like Uncharted 4, Gran Turismo, Horizon etc will entice more publishers to sign with Sony for either timed-exclusivity/DLC or full console exclusivity and marketing deals. I fail to see how someone like EA or Ubisoft wll support the NX to the same extent as the PS4 and Xbox 1 considering there haven't been Fifa, Assassin's Creed/COD etc on a Nintendo console for years...
The only way it can be successful is if they go the Wii route, by doing something completely different to Xbox and Playstation. Going directly against those two is commercial suicide as third party games don't sell well on Nintendo consoles and they would be going up against a combined user base of over 70 million by years end. Just my opinion.