I think I mostly agree with you, but I think some skills (or the process of learning them) predictably influence one’s values and behaviour in undesirable ways. In case of social grace this influence can be “I have the feeling of small changes in my social capital depending on what I say → I have frequent reinforcement based on my social capital → I value my social capital more → I’m more reluctant to spend my social capital on saying honest things”.
And yes, avoiding this influence is just another skill one can learn, and perfect rationalist definitely would have it, but learning it isn’t free.
Really? I thought only medical/legal/financial professionals have to write “not a medical/legal/financial advice” disclaimers. (I’m not from US)