To be fair there are other ethical systems which are just as bad if not worse than moral relativism when put into practice. For example utilitarianism which is based around making the greatest amount of good for the greatest amount of people. While in theory this looks good it can allow some pretty horrific things to happen. for example if the majority of a country’s population decided they wanted to wipe out a minority group then that would be morally just under utilitarianism. Therefore if you follow this theory you could support Germany’s actions in the second world war in the holocaust. So moral relativism isn’t too bad if you compare it too utilitarianism.