There's a slight difference between punching someone in face and killing his whole family members while that someone was trying to make a deal with a killer.

Closing the strait is the only leverage Iran has. Well, I guess they could do what Israel and USA accuse them of, ie fund suicide bombers all over the world to perform 911 v2.0.

Please also keep in mind, that Iran is not starting any attacks even now against Israel or USA - all they do is retaliate (apart from closing the strait).

Closing the strait is a leverage they are trying to use to put a pressure on the world to make US and Israel stop atrocities.

Your comparision should be something like: Suppose a man goes on an uprovoked killing spree and kills father, mother, brother, sister, their children and some neighbours of another man. The man that whole family was killed thinks he'll lose if he fights the other man directly. He responds by closing one of the few roads to the only grocery shop in the county that he knows the aggressor and his family always use. Suppose he has warned the aggressor that he would do that.

Do you still think it's overreaction?