Is it your stance then that there is no circumstance we could agree is universally "bad"? Let's imagine a virus comes into being that infects every living being in the universe, and this virus puts every living being in non-stop, excruciating pain for an extended lifetime. Every being. Could we call that universe "bad", full stop?
Now a pure relativist can make the argument that there is no way to prove that such a universe is "bad". While I understand that stance from a pure logic perspective, it strikes me as a nonstarter from any useful perspective.
It seems to me that what almost all ethical and moral systems have in common is that they strive to improve the well being of conscious creatures. (So, for example, moral and ethical systems tend not to be concerned with the well being of rocks.)
Finally, to me, there is no point in interacting with pure moral / ethical relativists. Such discussions are pointless.
Ok but isn't the argument you just made relative to human well being?
Are such discussion pointless because there is no argument?
The only thing to argue is the viewpoint of the position one's morals are based on. The rest is simply how it works.