It's like the military says, "We can't make you do something, but we can make you wish you had."

People understanding the negative consequences of potential actions is a bedrock of society.

If a person is not amenable to acting out of compassion for others, they should at least have a fear of the repercussions for being violent towards them.

I believe that likely criminal punishment is absolutely a reason there aren’t as many murders as there could be.

I would agree that many (most?) people would not kill even if it was legal. But not all.