When a writer implements this, it becomes a real story.

Perhaps not polar opposites. They simply have different views. A republican and a democrat have different views, and may be seen as polar opposites, but they're both still part of the same thing. Politics. Good and evil are still part of the same system, just on different ends. One is living comfortably and doesn't understand the pain of those looking in from outside the window, trying to survive in the cold. It switches with every story, but the mechanic that the villain was just simply "there" and we should all accept he's just "evil" is something I hate. I like it when we get to see either A. If the villain is in power, that's how he was raised, that's what was drilled into his head. Or B. If he's the street rat type, he's simply trying to survive.

Pure good and pure evil are at separate ends of the spectrum, polar opposites, one can not be pure good with any amount of evil and vice versa, you can still slide up and down the magnet, but the ideological concepts are still at opposite ends. Your example of the politicians is irrelevant because they are not of either core belief. You can be a villain and be good, and you can be a hero that's bad, but at the end of the day, the concepts in their purest state are infact polar opposites. Which is fine, because they are what keeps the system together. What does the north and south end of a magnet do? They pull together. Without the opposite polarity the system falls apart

Ah shit I didn't see you comment till now I posted pretty much the same thing after you did my bad lol great minds think alike

You're both nihilist. There is no good or evil because the "bad guy" will always say the "Hero" is the villain, and vice versa. So who really dictates this?