It's not sarcasm (at least the majority of it isn't). And you're acting as though there is no true right or wrong, which is debatable. That's simply another opinion.
No, Eldin is just saying that it sucks that among different perspectives there is no true way to determine what is morally right or wrong which translates to smaller things as well. There is often a right or wrong although it is all based on human nature. If you saw an alien planet that had legal murder, you'd likely find it immoral and wrong but that's because human nature is different than that alien race's nature.