Like they feel obliged to.
We even do it to ourselves, cause ourselves pain, thinking it will help us behave better next time 'How could you be so stupid!' etc.
There are arguments for and against just avoiding people who do this pain-inflicting. But since 'these people' are most people, self included, if you get good at managing this cultural curse we have, you will become an amazing person, with a rare, useful skill.
Id like to some of that.
Reality-feedback is a multi-purpose problem solver. "Hey, I feel bad. Did you intend that?"
Imagine being told such a thing with a simultanious communication of love: held hands, hand on back.
Many a monster can be melted by simple illumination, just being seen.