The reason why I think it's important to have fictional conflicts set in the present, instead of keeping moving them forward, is because we're living in less-than-perfect times. And this helps to draw a parallel with real life. It doesn't matter that there were no Eugenic Wars in the 90's, because there were (and are) other problems; from global warming to genocides all over the world, so the metaphor still works. And the message is clear: "This too will pass. No matter how bleak the present looks, someday it will be better, we will be better." This is the source of the optimism in the series.
So there was no need to move the Eugenic Wars to the 21st century, because it was never intended to be a literal description of current events, but a parallel for them. Back in the 60's they had to know that most of the audience would still be around in the 90's, and that they'd see that there was no such thing as the Eugenic Wars. But those details aren't important; the message is.
So there was no need to move the Eugenic Wars to the 21st century, because it was never intended to be a literal description of current events, but a parallel for them. Back in the 60's they had to know that most of the audience would still be around in the 90's, and that they'd see that there was no such thing as the Eugenic Wars. But those details aren't important; the message is.