Indeed, I would prefer they not act, or rather - delegate their action - rather than literally firing blind.
A man or a woman cannot 'delegate their action' when in face of an imminent physical attack.
But they still have the moral obligation to see to their own defense, whether by learning to defend themselves without sight (doable, but not usually worth the effort) or by delegating that responsibility.
People have no moral obligation to learn to defend themselves and a right of self-defense cannot be delegated.
Certainly I have no obligation to defend them, nor does anyone else who has not explicitly agreed to.
If you do not have a duty to defend people, people also do not have a duty to defend whoever they choose, including themselves!
So, though it may be delegated, you cannot just expect someone to take care of it for you. It is your duty to see that it gets taken care of, just as with parenting.
No, self-defense is not my duty.
If you take away my ability to defend myself, you are taking the responsibility for that duty. You may not see it that way, but that is the truth of the matter.
A private school have no moral obligation to protect you after you VOLUNTARILY agree to enter without a gun, except if there was a previous explicit agreement between you and the school to determine the protection.