Cute ... have you talked to Gale after Rafaels visit?
There is allways someone who thinks he can outsmart the odds.
You did get cards ... play them right, and you will be rewarded ... play them wrong, and you will be dead ...
Odd, that everyone decided to get rid of them.

Literally nobody in all of Act 1 knows what the tampered-with parasite will do to them. They do know that the standard parasite normally painfully incapacitates the host in a day and kills them within a week. They might know that someone infected can turn within seconds if they poked a certain console on the mind flayer ship. No one even suggests - not even on the evil path - that keeping it is beneficial.
Someone on the evil path needs to acknowledge the existence of the parasite and suggest that it can be controlled, managed, and used for the benefit of the host. That would solve a lot of the problems, and give a motive for evil characters to keep it in. Even if the person on the evil path is lying, it needs to be said to get evil players a reason to keep it.