It is a way to direct and semi-control the actions of ignorant, self centered people without building a real world justice system.
It works only to the extent you can convince impressionable young minds to accept it.
For the less impressionable, there is enlightened self interest --- understanding and accepting that the world would be a better place for all if everyone would simply do unto others as you would have them do unto you.
Unfortunately, the latter has yet to reach a similar level of acceptance and popularity --- but there is always hope.
that's why i'm wondering: is there a way to meet these desires outside of organized religion? what would a non-deranged spirituality look like?
Reality, common sense and philosophy --- which makes it is a hard sell.
The easy sell is to offer something fantastical that is never delivered.