I think Nintendo thought 3rd parties would fill in more of the gaps.
But yeah, Nintendo could really use this time to build their personnel numbers. Honestly, buying some teams and letting them make whatever and throwing it on the eShop could be how Nintendo finds their next big franchise.
This is another thing that really bothers me with Nintendo. They hold such tight leashes on how certain things should be done that a lot of potentially great ideas were probably tossed away before it could be really thought out. Their development teams may be creative, but their execution is so conservative and set in their own ways. I'm not sure if that is how businesses in Japan work in general, but in my brief time traveling in Japan, I noticed that they have a really disciplined but restricted caste system. You are pretty much doing as you are told. You do not question the higher ups. They do not respond well to changes. I think Nintendo in some ways falls into this category.
If third parties are not willing to develop games, they have to either create their own teams and build up their talent or buy the whole team. I'm sure if they are open-minded with their development, talented individuals will seek them as well. Most of us grew up with Nintendo and the same people would love to develop for the company they were so fond of back in the day.