Likewise, you can't attribute all the ills of the world to the Ascians. The sundered all on their own are capable of unimaginable cruelty as we've seen repeatedly starting as early as level 15 in ARR.
Words are easy. Fact of the matter is telling people who've survived a horrific apocalypse where their loved ones were forced against their will to conjure creatures of nightmare that devoured people in the streets, then had more loved ones volunteer to be trapped in indefinite purgatory within Zodiark just to make it stop, that in their moments of trauma and grief need to move on is incredibly tone deaf. Not to mention that returning to the star was a core and important part of their beliefs and those who'd sacrificed themselves to save the world were now prohibited from doing that.Also, the rejoining wouldn't have happened if the Ascians had accepted their world was over or actually tried to do the same, WoL, do, try to improve their lives instead. They're the culprits and the ones responsible for the rejoinings in the same way Venat is responsible for the sundering.
Frankly, I think the game did a poor job of depicting how terrible the Final Days actually were (not helped by the fact that the return of them amounted to virtually nothing so the sundered never got a true appreciation of what the Ancients went through either). It's more like your loved ones are now POWs, but instead of trying to rescue them you should just forget them and move on with your life. No one would do that, especially when they had a means of bringing them back.
Venat didn't give the Ancients any context as to why they should change (not that it mattered because someone was always going to have to face and defeat Meteion, embracing suffering and despair wasn't going to make any difference in that regard). It was basically:
Ancient1: We have a plan to release those you lost.
Me: Great, do it!
Venat: No, don't!
Me: Why?
Venat: Because...! Reasons.
Me: Uh, that's not good enough, go ahead with the plan.
Venat: *sunder* That's what you get for not doing what I wanted!
You're just reaffirming what I said.Links Venat had accounted for (she was the one who carried Emet to the aetherial sea).