Gun control is an issue that needs to be worked out. The bigger issue IMO is what is making these mostly young men/ boys want to commit mass murder.
It's a combination of things. This monster's mother said he had a really bad temper and flew into rage a lot over video games. Apparently the inciting incident that kicked off this massacre was his grandmother shutting off the wi-fi. The internet allows disturbed (young) people to find each other and enflame their hate. Who knows what kind of other mental issues he had.
So take all of that stuff, all that anger, all those mental problems, and add an AR to it. Recipe for disaster.
I agree that this country has a mental illness problem it doesn't want to confront, but the ease of access for guns in many states is basically dropping weapons into the laps of unwell people. You don't let toddlers play with knives; we shouldn't let everyone have free access to ANY weapon, much less an AR style weapon.
I doubt this shooting moves the needle at all. The gun lobby is hunkered down and the calls for gun control will die down in a week or so until the next mass murder.
This is America. Everything that's come before has led us to this.