He does make a valid point, it would be really hard to convince ps4 users to buy an XB1 and even vice versa. The overlap this generation actually seems smaller. 

This might be the best comment I've seen in weeks!

It wasn't that hard to convince PS2 users to buy Xbox 360s, or Xbox 360 users to buy PS4s. Generational jumps leave behind brand consumerism when it comes to how the actual market works.

NX could convince people from PS4/X1 to move to it. Third party games, however, are a big incentive of it.

EDIT: and I also forgot to mention that despite poor Gamecube sales, everyone owned a Wii. So yeah, convincing people is easy when you do things right.

However idealy if Nintendo device is mainly based on it being handheld mainly, how could they possibly convince Rockstar to make that game for them. I think Nintendo will get some third party, but the third party that the 3DS enjoyed. 

Also Wii was convinced without third party (since you added Wii comment). 

And it wasnt hard to convince both to buy a Wii. It was simply a matter of price. 

If Nintendo could convince Rockstar to put one of the best GTA games on the DS, then it's a matter of Nintendo not trying enough this time.

Also, Just Dance numbers could say otherwise in this regard. That's a third party game and it made massive numbers on the Wii.

Yes, but Nintendo will most likely try to capture that level of third party. The Just Dance crowd, it is has been clear for awhile they cannot seem to grasp the third party AAA  development crowd. 

Is this surprising at all?

Because they've given up on it, and that's what ultimately will make them bite the dust, once again.

Nintendo is used to not getting 3rd party support by now.
Unified games library, and cheap entry price point (so people also get it as a 2nd console), is all thats needed.