I still think alien parasites in your brain is just disgusting.
Roleplay-wise 99% of sane characters would want that thing out of their head asap. And the game just won't let you. Larian decided
you will use our fun powers. This is an RPG, not a platform game where you collect fun powers and story doesn't matter.
You don't need the tadpoles for plot device beyond Act I, after you have joined forces with unlikely allies and learned what's going on. After that, becoming a hero or a villain in the events of the game is motivation enough. They should have offered a way to extract the tadpole at this point.
And it just gets worse and worse when the emperor starts broadcasting in your head. Probably the Ring of Mind Shielding I've always been wearing is just a pointless trap item at this point, too.
So yeah, it does smell like gameplay devs calling the shots again and wanting those powers for all players, panicking last minute about late game not having enough progression.
Yeah, it is disgusting. However, if it were *just* that, I could envision a character swallowing their disgust and going through with it in order to gain psionic power. As it is, though, it also damages your brain and undermines your mental integrity, making you less you every step of the way. And to do that, you must be utterly mad.
As for not needing it beyond Act I....it is interesting that being in the middle of Act II, I don't recall a single dialog line in Act II where I can use the illithid power I got from my original tadpole. I don't think they were ever meant to be removed early though, and I'm ok with that. I find it a much greater dissonance that the sense of urgency you have in Act I conflicts with the desire - and the need - to explore the region before you go on with the plot.
About your last point: unfortunately, rule of cool conflicting with basic common sense isn't exactly rare in games. In the light of this, it is perhaps not so bad that there are no consequences attached. I can pretend it's all gameplay, pretend it does not exist. I just made a new Great Old One Warlock, the only kind of character I can envision who might conceivably be mad enough for this, but I doubt I'll be able to do it even with him.
