Whilst there are lots of grey areas around gun ownership there is a simple reality. Every year thousands of people die as a result of gun related incidents in the US, far more than per capita than most other countries, especially if you look at moderate democratic countries in Europe.
If nothing changes in the way America approaches gun ownership either legislatively or culturally then America will have to accept that incidents like Columbine, Sandy Hook, Orlando, Virgina Tech and Las Vegas etc are going to continue to happen. By accepting that the incidents will happen then by implication you are accepting that this is the price to be paid for maintaining the gun culture that exists.
I am not advocating changing laws for the sake of it, especially when the root problems for a specific crime may lie outside of what can be legislated (e.g. mental health or criminal activity for example). I understand that for those determined to do something then the law is no deterrent. I also understand that removing guns does not remove the threat of death through some other criminal and violent act.
What I don't understand is the apparent lack of will to formulate some kind of change. Those like the NRA simply throw the same arguments out that absolve anyone with a gun of any responsibility. Politicians can do nothing due to the gun lobby. Those representing the so called responsible gun owning citizens want to maintain a position where there is no restriction to the type, quantity and capability of weapon available.
Just because the problem is complex does not mean those with a vested interest cannot even try to work things out to have some positive effect on it. From what I can see, everytime something like Vegas happens the gun lobby put their hands over their ears and shout "lalalalalalala nothing to do with us". Change is formulated through discussion, compromise and a willingness to accept responsibility where responsibility is due. This seems totally lacking in how the gun lobby approach the problem.
As for the argument that citizens need assault rifles cos the bad guys have them.... that's what the police and army are for.