I typically ignore arguments that resort to "Have compassion!"

Because the inference is that we dont.

You know whats compassionate? Slapping someone over the head when they do something stupid, so you teach them the lesson not to do that thing again. Its more important to ensure you teach someone they screwed up adn to avoid doing it again, than to shout about "Oh, theyre just young and foolish and didnt know better!" The former makes them more aware and better prepped to deal with things in the future. The latter absolves them of responsibility, denying them the opportunity to learn from their mistake by brushing said mistake aside as a "foolish thing" outside their control.