For sure Nintendo have always been very reasonable on their growth and investments, and having a stable activity, people that stay in the company for years etc... All of this work towards making better quality products overall.
Of course everything isn't perfect, but they have great control over what they do, how they do it, and how to guarantee they are doing it right with a level of quality people will expect from them.
Their direction and communication are clear, people know what to expect as well on that regard.
You cannot even hope of reaching such stability on all regards with the chaotic approach MS have, obviously.