Stability is the first concern with anything. Civil Rights, which are important, wont mean anything without stability and is so a luxury they can't dive into.Businesses are after money, not civil rights. In the end, that's all it comes down to. 'Less Ninty has taken open stances on past societal issues, there's no reasonable expectation for them to prioritize social commentary over profits. Which is a cryin' shame.
Nintendo also views their games as art and art is very hard to make a living off of. If your art is made to put a smile on someone's face or invoke their wonder and emotions than bringing Civil Rights and politics into such a thing is the worst thing you can do to an artist (unless the entertainment is a criticism/satire of such issues which I doubt Nintendo does such things).