Why There's People Talking Past Each Other?

Via MonkeyCage, here's a map showing school shootings in the US over the last 15 years. Not sure of the criteria, looks to be a rather low bar.  But two things struck me:

• a lot more shootings than I would have thought because it's not limited to mass shootings
• the wedge of states with none:  Montana, the Dakotas, Wyoming, Nebraska, Kansas look to have no shootings.  I'm guessing, but I'd suspect these states are mostly rural and mostly retain the hunting culture I grew up in, a culture where kids went deer hunting when they were old enough, having a 30.06 rifle was a mark of maturity, and handguns were things brought back from WWII.  I suspect it's also an area with strong NRA representation.