How abooooooout we led the people in charge of creating BG3 decide what is to be in the game and what isn't? I've seen so much whining all over about the "need" to have her available for all kinds of characters (goody two-shoes included). This isn't Skyrim, you don't get to be Archmage without being able to cast one spell. This is exactly what people wanted - a game with consequences and with huge replayability. Larian has delivered, 100%. Even with Minthara's current buggy state, it's still amazing that you can actually recruit her at all. I'd be happy if she was literally just a henchman after getting her as a companion, it's still more than most RPGs offer these days.
She was always intended to be a companion so this is a bit of a reductive way of looking at it. Yes, Larian is doing a lot better with a lot of this stuff than most RPGs have done. But they also have a track record of fumbling the finish line and wanting/needing to do big content updates. Leaving her as someone you can only recruit by specifically NOT killing all the goblin leaders would be fine, if going that route wasn't so punishing or at the very least had unique content unto itself. I love the idea of losing party members over how you approach that. But between how much you lose and the absolutely nothing of value you gain from raiding the grove, and how you can clearly tell the journal and tieflings bug out if you
get Khaga to stop the Rite of Sylvanas thus ensuring the safety of the Tieflings and then proceed to Act 2 without killing all the leaders or raiding the grove,
there's just no real incentive to approach things that way except Minthara herself. It doesn't make sense. The Evil path was pitched as this interesting alternate way to play and quite a bit LATER that's more true, but in Act 1 it turns out there's nothing much unique about it EXCEPT having sex with her and a little bit more context in the post nut clarity which imo is a bit of a bad look. Why is sex the primary reward for atrocities when the punishments for it are so much more true? Even trying to True Neutral your way into Act 2 has most of the same big content losses as going evil, you just mitigate the party specific losses.
The more I think about it, the more there just flat out isn't a reason good enough to leave her recruitment restricted like this. Halsin's limitation makes sense because he's intrinsically tied to the druids and the Grove which makes it all the more hilarious that he's still good to go if you
cause chaos and kill all the druids independent of the goblin situation.
Minthara is not intrinsically tied to the goblins, she's being mind-controlled and it's typically a good guy move to help with that sort of thing even given the reverse mindbreak tag (a phrase I never thought I'd say). So she should still be good to go if you eliminate the goblin threat as long as she's not dead.