Right. Because there isn't a story a day where some local Barnie Fife panicked and shot an innocent bystander in some incident.
https://www.nbcnews.com/news/us-news/mississippi-police-fatally-shoot-man-wrong-house-while-serving-warrant-n786681
https://www.cnn.com/2017/12/30/us/kansas-police-shooting-swatting/index.html
https://www.usatoday.com/story/news/2017/11/10/rhode-island-police-shoot-kill-man-truck-while-hunting-suspect-stolen-cruiser/851523001/
I don't know about where you live but my local constabulary is staffed with a bunch a para military filth who were too unstable to pass the state police test. They are barely qualified to operate a pen to write a ticket. I would also like to remind you about the quality of the Broward Sheriff officers.
@Frank Cannon Frank,who says school teachers can't be former or retired infantry soldiers or infantry Marines? Those are the only ones that really qualify in the "soldier scenario" because they are the only ones that ever meet the enemy eye to eye and shoot him or her with an individual weapon.
I personally know of two highly-experienced career Special Forces soldiers who retired and took jobs as school teachers. If they were allowed to be armed at school,anybody that tried to gun down students in their classes would be in a heap of trouble,and end up turned into a heap or rapidly cooling meat. Not that they or anyone else would look forward to doing anything like that,but when duty calls,and teachers DO have a duty to protect the children they teach.........
Also,as others point out,probably fewer than 90 percent of the members of the US Army or the USMC are infantrymen who carry weapons and have shooting people with it as a basic job requirement. They are cooks,clerks,personnel specialists,truck drivers,band members,etc,etc,etc. When you get to the US Navy,the US Air Force,or the US Coast Guard (which isn't even a part of the military) not even 1 percent of their members ever even touch a firearm. Or at least don't touch one on duty. Lots of them like to hunt,target shoot,gun collect,shoot skeet or trap,etc,etc,etc,just like people in all other occupations.
There is no perfect plan. Even trained infantry soldiers sometimes freeze and refuse to shoot. There is another thread that mentions General SLA Marshall and his studies that prove that out of a squad of 10 infantry soldiers,typically only 2 can be counted on to take careful aim at and shoot an advancing enemy soldiers,2 can be counted on to not shoot at all,not even to save their own lives,and the remaining 6 will point their weapons in the general direction of the enemy and shoot without aiming. IIRC,he started this investigation when it was discovered that there were dead American soldiers in their fox holes or bunkers who had been overran and killed by the enemy who had fully loaded unfired weapons. It was Marshall's observations and recommendations that led the US Military to abandon the policy of having ONE fully automatic rifle (BAR) per infantry squad that had been policy ever since WW-1,and to adopt the M-14 with a selector switch that allowed either semi-or full auto fire. If most of your soldiers are going to refuse to aim before they shoot,they might as well be spraying so they have a better chance of hitting SOMETHING.
BTW,it should go without saying there should be NO "spray and pray" going on in school hallways,and in general cops are a LOT less experienced than soldiers.