"Treating a machine like a human" is a two-party interaction. Of course the layers of matrix multiplication is unaffected by this, but I think that we are not. It's a great opportunity to exercise consistency and dedication to the beauty humanity is capable of and this extends to the entire gradient of conscious/sentient entities.

It's as silly (to me) to argue that it's degrading to people to treat non-people well. It seems self-obvious that the inverse is true. It benefits the do-er of the deed and makes it that much easier to spread good will when applied to situations where it doesn't matter on the other end. It shows good stewardship as well.

I'd also make the argument that as inference becomes a feedback loop into training, it only reinforces that we're probably going to benefit from future models ingesting data containing unnecessary politeness.