Nintendo leaving the door open for 3rd parties never works out. If no third party wants to launch a major effort at launch and are all doing the wait and see approach then imo you just do what you gotta do.
If they didnt wanna hurt third parties then I still dont see why end of April is their next big title. You have 1 retail game coming in that span from third parties. Why care this early given they are not producing on your platform at all?
I'm not talking about the likes of EA and Activision regarding support that isn't there. I'm talking about those that ARE.
If the Switch launches day one with Zelda and Mario Kart, then who is buying Bomberman, Fast RMX etc? Zelda is a lock for most day one buyers, but I think Mario Kart launching alongside it sucks the air out of the room for everybody else.
It looks better on a list and I personally wish we had it now, but I'm not convinced releasing MK8 now is better for business.