If I understand you correctly -- your definition -- then our entire legal system is built on moral relativism.
For instance, in god's eyes it probably makes no difference whether you still a dollar or a million dollars. Under the law, it's the difference between petty larceny and grand theft. And then there's questions of "mens rea," that concerns state of mind of the person who committed the crime.
In order to banish this type of "relativism" from public life, it would mean creating a taliban type theocracy, which nobody really wants. They had a pretty firm grip of absolutism. And it got them nowhere fast.
Your argument is fallacious. Look at the laws that were in place one or two hundred years ago.
Basically what you're saying is there are only two options - an amoral free for all, or a Taliban-esque dictatorship where the Ministers of Vice control check women in bags to see if they have nail polish on.
I notice that people who like moral relativity always bring in the Taliban as a bogy man.