Sure they do.... Until some crazy person comes in shooting because they know no one there is armed to stop them.
Which is why screening of who is allowed to buy guns is crucial. It should be difficult to get your hands on an AR15 or similar type of gun.
I had a Federal Firearms License for 9 years back in the late 90's into 2000's. This is a license issued by the BATF that allows me to buy guns wholesale and sell them to the public. I got a license to buy old military rifles cheaper, most all relics which is part of my interest in military history. I had to have people fill out the paperwork. This was when the Brady Bill passed and I had to call in background checks on buyers.
The way background checks works is this: you call the number and tell the person (or leave the info on a recording) the data about the buyer of a gun. If they didn't get back to me within 3 days the buyer gets the gun even though the background check wasn't conducted in time. Usually they got back to me within a day. But they were understaffed and many people got guns without a check. Not a good system. I'm not sure how it is today.
One of the hand guns I sold ended up being used in a robbery. The police came in and asked for the paperwork of the buyer. He checked out. He later sold the gun to someone else. That guy sold it to the criminal who used it in a crime. There is no law that prevents a gun owner to sell a gun they legally bought to a criminal. There is no background check.
The really bad story was about the guy who bought five AR15s.
He was the coworker of a friend. He came in and bought two in one purchase and three a week later in another purchase. He did this for a reason. He knew if a person buys 5 or more guns at once I had to fill out a separate form and send it to the BATF. He'd be on their radar, and he didn't want that.
He passed the background check. About a month later he came with my buddy and me to shoot on the Kansas river between KC and Lawrence. We did this near a shooting range club, maybe 1/4 mile away.
We set up targets on sand bars on the river. After about five minutes we had things set up and Tim opens up with his AR15 fully automatic. I asked him if I could see his gun and shoot it and he said yes. I confirmed it was fully automatic. This is a serious federal crime. I said we all need to leave right now. Get your stuff and let's go. If the sheriff catch us with a full auto gun we are all going to jail. I was hoping there wasn't a cop at the shooting range who heard it.
It turned out Tim had sold three of the guns to friends. That is three counts of the federal crime of a "strawman purchase"
It also turned out Tim and his friends were these sovereign citizens who don't recognize the authority of federal government or even any governments. Why didn't I call the BATF about this? Well how can you trust guys who have no problem converting guns to full auto? Who have disdain for the rule of law?
After that I can't see how we can trust ordinary citizens to get these military guns. They may pass background checks but that doesn't imply they are mentally sound and responsible. Even if a person is good, there is no system that regulates who can buy a gun second hand.
I think there needs to be a set of laws that heavily regulate guns. The military-based guns need to be very, very hard to get. I think requiring licenses for gun owners and training and requiring sales between citizens need to go through a dealer and the buyer have a background check.
I can't see guns being outlawed so we need to be very specific about how people can get access to them.