I like the cigar ending on Avernus as well, but I honestly would not have if I romanced her, so I understand the frustration from people. I send Wyll with her and it's all good, I'm happy for them, since neither have as much to look forward to on Faerun anyway (unless I romance Wyll, then there's really no positive outcome). But every other origin companion has the possibility to have a 'settle down together' ending. Giving one of those to Karlach doesn't mean they need to remove the Avernus ending, it would just give people the choice to do otherwise.
