My godness I've been scrolling through this thread for a few day now and my god what an ungrateful bunch you are. Karlach is supposed to be a doomed character, I don't know why you just wont accept it. By god Larian even rushed and added new cutscene just for her, and it's still not enough for you. Clearly there was no plans for her to have a good ending, and it becomes obvious when you listen to devs. They seem to be happy with her story as it is, they think its the fate she deserves and thats it, its their story they can do whatever they want. Just accept it
Don't appreciate the personal attack, but that's fine.
"Karlach is supposed to be a doomed character" -- citation needed. Nobody has ever said that. Not Swen, not the devs. No one.
In fact, everything that's present in the game points in the other direction -- the abundance of enriched infernal iron and a bunch of advanced infernal engine mechanics. But you can't interact with them on that one conspicuous point. A bit of a coincidence, don't you think? Doesn't help that Dammon's VA accidentally admitted to there being voicelines of her getting a fix recorded. If she was planned to be a doomed character from the get-go, why have them?
Her Avernus scene filled in what was once an abrupt cut to black when you chose that option. We appreciate the effort they put into it, and some people love that ending as a whole. But we asked for a fix, we didn't ask to send her to hell.
Lastly, getting railroaded into one particular narrative in a game about choices is the last thing you should expect.