"Mass shootings" are the bogeyman because the Media makes them a big splash. Like an airliner crashing which kills many at one time, they enjoy promoting calls to "do something" yet airline travel is statistically one of the safest. Violent crime, including homicides committed by people with guns has been trending significantly down for decades, yet the media wants you to think we have to fear mass shootings more than any other activity. You want to remain significantly safer? Don't drive, or ride in a motor vehicle.
As human being we tend to overact with emotion, to "do something" even if we know it will be ineffective, or perhaps counterproductive.