When did it become a norm?
"Act only according to that maxim whereby you can, at the same time, will that it should become a universal law."
However hindsight is 20/20 and you can't make rules for everything
Wanting to make everything an universal law is missing the trees for the forest.
Because things change and situations change and what has worked before may not work anymore or have a detrimental effect.
Violence might not be moral, but it works.