As I said up above ...
This security protocol is not for the crazed and criminally insane person. That is going to take armed personnel to deal with them.
What this security protocol is for - is related to the paperwork that you sign upon enrollment, which tells the school who is allowed access to your child. They are following that legal paperwork that was given at the beginning of the year.
Ah, the magic paper again!
So this has nothing to do with the safety of the children but is there so the office drones can force others to bow to them before they can see their own children.
Doesn't that seem sort of mentally unbalanced?