No signs point towards a scenario where things get better after people die. Our political system is a sick one. Expect no change.
You're right, we should have immediately banned all firearms nationally to prevent something like this from happening again, trampling all over the 2nd amendment. (nevermind how the hell you'd implement it without a thousand Ruby Ridges and Wacos, or why you expect to find more than a third of the guns in the first place [0]) It's not like he could have crashed a plane loaded with AMFO into the crowd instead, right? Or maybe we should just expand California's gun laws nationally, since that's worked out so well to stop the mass shootings there.
You say "OMG how haven't we fixed this, it must mean we don't care" while proposing no solutions, for a problem that might not have a solution. Britain still has terrorist attacks (vans, acid, knives) and that's after banning carrying a fucking butter knife. Humans will always find ways to kill each other, (checkout improvised prison weapons sometime) let's not go too crazy hunting down one of the smallest sources.
So, maybe our response to shootings shouldn't be compared to our response to crumbling infrastructure. At least with the infrastructure, there's a path forward that almost everyone would agree would work. That's not the case with guns.
0: http://reason.com/archives/2012/12/22/gun-restrictions-have-...
Yes.
Britain, and specifically London, seems to rival Paris and Brussels in terms of gang violence, but you still get a lot less dead people than in the US. You're suggesting there might not be a solution, yet practically no Western state except the US has this problem in the first place.
Citation needed. A cursory look at Wikipedia for suicide rates suggests that they took a dip in the late 90s but otherwise are flat from the 80.
Violent crime has been trending down for decades.
https://en.m.wikipedia.org/wiki/Suicide_in_the_United_States
https://www.statista.com/statistics/191219/reported-violent-...
Though I'll continue to argue that this is still kind of unacceptable, since a constant rate over an increased population means more people dying.
1: https://www.washingtonpost.com/news/to-your-health/wp/2018/0...
So that's 146 who died due to an effort to take their guns. Let's not repeat history.
On a similar note, there was the Waco siege. That was also an effort to seize guns. There the US government killed 76, which is also worse than the Las Vegas incident, but partly done by burning people to death instead of shooting them.
You'd have to have a very special configuration of what to include as mass shooting for Wounded Knee to count but none of Antietam, the Lawrence Massacre, the Opelousas Massacre, the Greenwood Massacre, the Fort Pillow Massacre, the Bear River Massacre, any number of major attacks in the California Genocide, etc., to be included.
But, by the usual standards, neither those nor Wounded Knee are included in the scope of that term.