I know. I'm saying, more people should get them. If even one guy in the crowd, or near it, has a gun, retaliation and a stand off can take place to at least stall the offender till help arrives.
Hell, if they're a good enough shot, and are packing some massive balls, maybe they could even take the perp out before then. I'm not saying that "average joes" should go get one. You would have to be responsible and know what you're doing and be a decent shot.
We have open carry in Alaska. You can be at the store and walk by a guy with a gun on his hip.
If you plan on using a gun in something like this you need to go to a shooting range and practice, practice and practice and the practice some more or you might shoot more people than the bad guy.