There are people who have minimal impulse control, and such people are properly prime candidates for removal from society.
I think people have all kinds of crazy temptations, regarding things many of us would find repulsive, but that, by itself is not dangerous. If they resist those thoughts, or keep them firmly in the fantasy world, then no harm is done.
What is dangerous is the inability to separate temptation and fantasy from their own reality...the inability to move away from those things to better thoughts.
Notably, while mere drug use might not be harmful, it does lower inhibitions. Drug abusers are far more likely to act on impulse.
Now, having said all that, what the hell do I know? I'm not a trained psychiatrist or whatever. I just think people need to consciously choose to (1) keep their fantasies away from reality, and not try to realze every temptation, and (2) cultivate a lifestyle that encourages positive fantasies, and discourages negative fantasies.
That is one reason I like the Catholic Church so much...I think over 2000 years, they have developed a pretty good thought system to do that. I hope my kids use that thought system, because if they do, they are far more likely to lead happy and fruitful lives in the here and now. Granted, there is the reward in the afterlife, but I happen to think a good Catholic life also leads to maximizing one's happiness now.
Just some random thoughts prompted by your post, but not directed to you.