Beyond normal consequentialism (as discussed in other answers), there’s a game theory angle, where if you aren’t trying to model a norm into existence, it’s worthwhile to only follow the norm once it’s agreed violators will be punished.
See paulfchristiano’s post on Moral Public Goods, which argues that you will often get into situations where people would be in favor of a norm were that norm enforced, while not being in favor of the behavior the norm calls for when the norm is not enforced.
Beyond normal consequentialism (as discussed in other answers), there’s a game theory angle, where if you aren’t trying to model a norm into existence, it’s worthwhile to only follow the norm once it’s agreed violators will be punished.
See paulfchristiano’s post on Moral Public Goods, which argues that you will often get into situations where people would be in favor of a norm were that norm enforced, while not being in favor of the behavior the norm calls for when the norm is not enforced.