If Nintendo doesn't get the big western third parties on board, they aren't going to sell consoles. Period.
I am certain that if Nintendo releases yet another underpowered first party box with a gimmick the NX will be a failure. The appeal is just NOT there for the masses, no matter how great their games are.
Too bad Nintendo doesn't see it that way. The Wii gave them a taste of unprecedented success while completely disregarding industry trends, so they'll try their hardest to repeat this feat, no matter how unlikely it may be.