I think it does make a good point though. The intellect devourer is certainly not the only thing that's horrific/disgusting in the game.
No one said it was. The argument is that it goes to a different level than scenes like the one with the fishermen, and is the only scene so far that does so.
However, if you're not prepared to feel a somewhat disgusted or horrified during some scenes of the game then I think it's best that you sit this one out.
And the argument here is that digging someone's brain out of their skull with your bare hands in a cutscene close-up goes beyond being somewhat
disgusting. I played both Divinity: Original Sin
games, both rated M, neither went for gross-out horror on this scale. Maybe they would have if cutscenes were a thing in those games - close-ups of elves feasting on body parts anyone? - and they're taking advantage of their new toy to play around in a way they couldn't before, I dunno, but I hope it's out of their system.