The problem is that you are not dealing with rational people here, you are dealing with extreme religous fanatics. They are either not afraid of dying and becoming martyrs, or they are afraid but dare not show it.
I'm not saying either view is right, but reducing the Iranian government to irrational religious fanatics is intellectually uncurious and unempathetic.
[1] - https://i.kym-cdn.com/photos/images/newsfeed/002/355/607/670
I'm British, and whilst I don't think my government is perfect (their stance on digital privacy is insane) they are not murdering people, and we can vote them out at the next election if we want to.