Sony and Nintendo are going neck and neck with the Switch and Sony, the Xbox One is a distant third. Gamer don't seem to care third party are marginally better on the One X because of the high price point and Sony is just killing at 1 st party game. They already had Detroit and God of War and are showcasing 4 blockbuster 1st party games this year @e3, Microsoft can counter at best with 1-2 exclusive games and some third party content and at this point they need to so much better than Sony to even out the playing field and I'm not sure if they can even be competitive.
First party, second party and exclusives have ALWAYS defined the image of console. Because no matter how powerful of a console you have, you cannot have those fore mentioned games on that console. And this whole "I just like third party games" to justify an Xbox One (not to say that there aren't other reasons that make the One worth the purchase) is a very sorry excuse. Easily, Sony's console (for example) offers exclusive titles that are also of the same genres as those third parties games. So you get more game, more choices.