Let's say I disagree with your assertion that humans, on average, are more receptive to cold or robotic sounding text. Who's right? In the chess domain these sort of questions can be posed and answered trivially: play a zillion games against yourself testing both sides and you can objective and perfect data on which is probably superior.

In the human domain? It's possible, if not probable, that there is no answer. It comes down to interpreting and measuring things that are effectively impossible to quantify, and vary dramatically by group of people. People coming in while not-quite-invisibly growing to loathe you and company morale collapsing is something that you can't put a number on.

And this is just one tiny aspect of all of the different factors that human managers have to deal with constantly.