What lore do you ignore?

[Lady_Silvermoon]

And my issue is that they're trying to write a story of hope for a world which, for plot purposes, does actually need to be irrevocably doomed or you can't justify the decision to abandon it. Nobody within the story deemed it as disposable until there was (allegedly) no other path possible.

On the other hand, your proposal that we should go back to Elpis and change the timeline would be deeming the present-day world as disposable just to take a shot at saving a newly created alternate version of the ancient world, while not actually saving anyone who already exists.

But we already know from G'raha's continued existence that divergent timelines exist and are possible. There is no justifiable and moral reason to know Venat is going to kill all these people and say nothing to them. And no, she didn't simply transform them, she exterminated them, else Vauthry only transformed the people he turned into sineaters and Athena only transformed the people she turned into...whatever she was doing.

While you can question if the alternate Ironworks had he right to do what they did given they didn't know if they'd be wiping themselves and everyone else in that timeline out of existence or not. Insisting that they must be without hope to justify putting their resources towards helping others goes against the themes of Shadowbringers. We are told planting seeds we'll never see grow is in our nature. That paying it forward is the good in us. I think that's a much better moral than entire disposable civilizations giving everything up to their betters.

ETA: Also, we opened out fat mouths to cause the genocide. Why can't we keep yapping to stop it? You're arguing we can't say anything because it risks our timeline. But saying something is what puts Venat on the path of murdering her people. So we've already talked. Why not talk to some more people so she can be removed from said path we put her on?