It makes no sense, even by the logic that killing is only justified to preserve life. The part where you die is the part where they kill you afterwards. No one is going to wait until they declare their intent to kill you before fighting back. You take whatever opportunity you have because you might not get another one.

There are people in the world who believe no violence is justified ever, even in self defense, and they attack rape victims along with victims of other serious crimes, the military, etc. because they perceive people like that as threats to their insane ideology. They don't care about the hypocrisy of defending rapists and their ilk to do it. They care about holding back innocent people so that violence is never viewed in a positive light, and they do it at all costs.

True evil exists in this world and that is one of its many faces.

Also there is no way to tell if you will or will not be murdered right after, so you should very much consider your life to be in danger and act accordingly.