In fact, the message is better received when there's less intent to shame than there is to educate. Yes, people make mistakes and people forget. No one is ever exempted from the rule. I'm sure everyone knows how it feels. And yet we still think it's ok to be rude and condescending to others, when we ourselves hate it.
Of course I can understand being angry over big issues. But even then. There are certain limits on how you can treat a person. Small insignificant matters should not be blown way out of proportion just because you've had a bad day. Think before you speak, or write. Word choice has a strong effect on people. Yeah, sticks and stone can break your bones, but words can break your heart. And feelings are much harder to nurse compared to a bruise.
But even if we do sometimes over do it and blow our top for no reason, there is always a chance to apologize. And such behavior definitely demands it. I do believe deep down inside that it doesn't feel good to make someone else feel bad. Maybe in the heat of the moment yes. But later, there is always that doubt and shame, and regret. Fortunately apologizing and reconciling helps clear all that away. Clearing the problem with actually talking it out is always the better choice if not always the easiest.