I think third parties could come back.
Just not this generation.
Maybe the one after, at best.
I honestly think that if Nintendo can make the right arguments with their product, third parties would have no problems supporting it, "inferior" power or otherwise. Of course this requires that Nintendo have a product that is immediately approachable and understood as the "new" from all angles and that they show that they're willing to go the whole nine yards with regards to making it easy to develop for and maintaining relationships with the third parties so they're well informed of what to expect.