In talking about how you'd love to do it as a DM you're also highlighting an additional design failure - Everyone else just stands there and watches you feed your head to the Illithid and does absolutely nothing, and there are no options or prompts for them to do anything, in any way.
In fact, this is not true. If you start to "succumb" to the monster, then one of the companions will tell you "what are you doing, you idiot! get away from him!", in my case it was Astarion (I do not know what others say). And at this moment you still have a chance to move away from the monster. Yes, they don't kill him, but they don't "just look" either.
I've never died in this scene, never! Yes, I killed fishermen, or one of them, but die by monster? It is necessary to purposefully want it or be not very smart. At an early stage, it is clear that the creature can control you, game give you THREE CHANCES TO CHANGE your MIND. THREE WHOLE CHANCES. even npc tell you 'stop you're dumb!!!' and you still do it? You can safely interact with the monster and not die. Because you have three chances to leave. In this scene, everything is fine with game design, but you can argue about the logical thinking of some players.
