As we weep bitter tears of regret over the loss of the world of Superman 2020, we must acknowledge the dark side of that world.
Because the sixth--and most important--reason to long for the world of Superman 2020 is:
OK, OK, technically, they're not from space. And they probably don't call themselves Nazis...but when you talk of "pure blood" and make your symbol 3/4 of a swastika plus some random lines, I think we can safely call you a Nazi. Especially given your dogma:
See: Nazis--obsessed with space! They're SPACE NAZIS!!!
Plus, they're big on genealogy:
Quarter-breeds? Dude, you really need to chill. Who cares if your races genetic purity is being sullied, if being only 1/4 Kryptonian means you still get full super powers?? That is a bonus, in my book!
Look, unnamed Space Nazi leader--even if we bought your concern, it's a pretty slow-motion threat, right? One (increasingly diluted) offspring every generation? At this rate, your precious genetic purity won't be wiped out for a few gazillion years.
Plus, you obviously know the secret identites of all of these Supermen. So instead of blowing up New Metropolis (and killing millions of "pure-blooded" humans in the process), why don't you just put some Kryptonite-laced salt peter in their food or something? Find a way to render their wives infertile? Sure, blowing up space cities is fun, but it's kinda overkill, isn't it?
But Space Nazis are bad, right? So why should losing them make us sad? Because Flushpoint has taken the one negative aspect of the world of 2020, and made that xenophobia the defining characteristic of the government and populace of the nuDCU. 2020 may have had Space Nazis, but the rest of their world accepted heroes, and didn't reject them as aliens. It's no fun when EVERYBODY is a Space Nazi...
From Superman #354 (1980).