These things wouldn’t happen if everyone was armed, they say

From here:

Soon after Mr. Mateen first opened fire, he was confronted by an armed security guard who was an off-duty police officer, said John Mina, the Orlando police chief, at a news conference Monday morning. They exchanged gunfire. The security guard was then joined by an unknown number of police officers, the first to arrive on the scene.

In other words, the gunman’s actions were immediately met with an armed response. Did it help?