Suzanne McCarthy posts about 'human' as a noun. I'm not sure if I've ever encountered anyone saying that 'human' is not a noun. I consider it to be a strange enough view, given that the word 'human' clearly does gets used as a noun in all sorts of contexts. That's just a fact about the English language, and any dictionary that fails to acknowledge that is simply displaying ignorance. But then people who think some arbitrarily selected body of people can arbitrate prescriptions for what counts as English will come up with all sorts of features of common English that they will declare to be wrong.
While I do think it's a mistake to think 'human' is not a noun in English, I also think there are times when people use it as a noun that sound very unnatural to me. Sometimes it sounds much more natural to say 'person' or 'human being' or to change the syntax so the noun is 'anyone' or 'someone'. This is not because 'human' cannot be a noun but because using it as a noun suggests a contrast with other sorts of creatures. We can talk about what's true of a human as opposed to an ape. It seems strange to say that you went to answer your doorbell, and you discovered a human there. When you say that, it sounds as if you were expecting the neighbor's dog, an ogre, or aliens from another galaxy. Since Suzanne's post was about Bible translations rather than just good English grammar or style, I have to suggest that contemporary translations that use 'human' as a noun need to be careful to do so when it's natural to do so. Since that isn't always the case, other methods might be preferable so as not to give the wrong sense.