Where did I ever say they got a pass? I said that writing redemption arcs for them would be far more believable and plausible versus writing one for Zenos because those characters have qualities that make them redeemable—which you need in order to write a GOOD redemption arc that will not come across as some kind of strange fan fiction. Zenos does not. Giving him a redemption arc when there is nothing redeemable about his character would make the entire storyline implausible. Researching simple writing basics is all you need to tell you this.
A character has to actually acknowledge their wrong doings and take accountability for their actions—and then strive to be a better person in order for a redemption arc to work. Zenos does not do this. He never takes accountability for what he does. He never acknowledges that he’s done anything wrong. He never tries to improve or grow as a character. His coming to the end of the universe was not to help us or anyone else: it was purely to seek what he wanted, which was to fight us. None of these contribute to a redeemable character. He is a selfish, singularly-driven character; which, in and of itself, is not a bad thing. You can totally have characters like that within a story.
Contrasting to him, Emet-Selch, while admitting he would have done nothing differently, at least acknowledges that what he strove to do to save his world ended in failure—and he left what was left of the Source and its reflections to us in the end. Meteion realized the flaw in her desire to “save” us from despair when she realized that happiness cannot exist without the other. Characters like Ysayle realized that what they had done—even when they had good intentions—was inexcusable and instead sought to make amends. These are characters in which writing redemption arcs would be far more plausible. Not villains like Zenos.
And none of this is me “giving them a pass”. I’m just stating simple facts about the characters and applying successful writing techniques with regards to creating successful redemption arcs to them. There is a difference between that and me saying “what they did was a-okay, I forgive them”.
If you’re going to try to argue with me, try actually reading what I’m posting first. Or do some basic writing 101 research. It’s not that difficult to see that he’s not a character in which a redemption arc can be pulled off for and pulled off well.