right, I'm sure there are all sorts of scenarios where that is the case and probably the phrasing would be something like that seems slow, or it seems to be taking longer than expected or some other phrasing that is actually synonymous with the code is slow. On the other hand there are also people that you can say the code is slow to, and they won't worry about it.
>So no that’s not the proper way to talk to humans
In my experience there are lots of proper ways to talk to humans, and part of the propriety is involved with what your relationship with them is. so it may be the proper way to talk to a subset of humans, which is generally the only kinds of humans one talks to - a subset. I certainly have friends that I have worked to for a long time who can say "what the fuck were you thinking here" or all sorts of things that would not be nice if it came from other people but is in fact a signifier of our closeness that we can talk in such a way. Evidently you have never led a team with people who enjoyed that relationship between them, which I think is a shame.
Finally, I'll note that when I hear a generalized description of a form of interaction I tend to give what used to be called "the benefit of a doubt" and assume that, because of the vagaries of human language and the necessity of keeping things not a big long harangue as every communication must otherwise become in order to make sure all bases of potential speech are covered, that the generalized description may in fact cover all potential forms of polite interaction in that kind of interaction, otherwise I should have to spend an inordinate amount of my time lecturing people I don't know on what moral probity in communication requires.
But hey, to each their own.
on edit: "the what the fuck were you thinking here" quote is also an example of a generalized form of communication that would be rude coming from other people but was absolutely fine given the source, and not an exact quote despite the use of quotation marks in the example.