The guard didn't intervene. The TEACHERS did by placing their bodies in between bullets and children. I would rather that these brave, fast thinking, heroic people have the actual opportunity to fight back. Their bodies likely saved lives by blocking bullets. If they had the ability to end the shooting they would have saved even more lives. Often even brandishing a weapon or firing it can end the shooting. Most of these psycho mass shooters commit suicide at the first sign of armed resistance.
This is true. How do you propose to accomplish this in a nation with half of the world's privately owned guns? Until your proposal is implemented, I'd like my little boys to be protected by people who are licensed, trained, and armed. What is your resistance to this? Do you think it is an endorsement of "all guns are good"? It is not. It is simply stating that people are safer with guards. Else nobody would ever hire armed guards.
Our president should be protected by ensuring they don't get into a situation where he is being shot at. Our Brinks employees transporting money to banks from Taco Bell or Albertsons should be protected by ensuring they don't get into a situation where he is being shot at. Our children should be protected by ensuring they don't get into a situation where he is being shot at. Yet all of these people get shot at and the best defense is to have armed guards. It has been this way since before guns were invented. In every society we have protected ourselves with guards armed with weapons, whether they are swords, spears, or guns. Protecting yourself with weapons makes you safer.