Guns only have two purposes.
a) HARM
b) KILL
No matter what people CLAIM their intentions for a gun is, if push comes to shove, all a gun can do for you is to harm or kill another human being. Are you willing to do that?
Keep in mind that crazy people don't concider themselves crazy. Imagine a world where all the insane people are armed "to the teeth". Threatening them with your own gun is not likely to bring them to their senses
You bring up an interesting point. Mentally or emotionally challenged people in the U.S. have very easy access to all kinds of arms. This issue has become epidemic here and very little is being done to help with the matter. A long time ago - back in the 50's and 60's, people who had obvious mental illnesses were often placed in mental "asylums' with little chance of getting out. I knew of one of these places in Georgia and the reputation of that hospital was awful. Because of public outrage, these kinds of asylums were closed down and non-existent by mid 70's.
Now, however, people who should be getting help for a whole host of mental issues aren't getting any and the problem has manifested itself in a problematic homeless population and a low income/high crime population . Couple that with the ability of these people to buy arms with or without going through lawful channels is pretty much arming and producing a very dangerous society.
A new problem has cropped up as well. Back in the late 70's children were beginning to be "diagnosed' with all kinds of attention deficit "illnesses". We have since come up with all kinds of new names for incorrigible children or children that need special attention from parents or teachers. We don't have time to counsel or parent these children so we drug them with these "cures". The result was that through the 80's until now we have a huge segment of our population that grew up drugged and without a clear understanding of how that has affected them. I think it is particularly alarming that the massive school shootings where several school children are killed or injured by gunfire starting with Columbine in the 90's and most recently at Sandy Hook were perpetrated by very young adults or teens with a history of being treated for various attention deficit disorders. I am no expert but it sure seems linked to me!
The U.S. does absolutely NOTHING to stop the flow of drugs, however. Our politicians including our President will not touch drug companies or question what the health industry does. There will be no massive study questioning what the long term affect these drugs are having on U.S. citizens - only an attempt to take guns away or pointy objects.
In the U.S., our country was founded on rebellion. One of our most important amendments is our right to bear arms and to form militia. This right was NEVER intended to protect the rights of citizens to hunt or to defend themselves. Its sole intention was to protect the citizen against the GOVERNMENT. So - when the government makes attempts with these kinds of tragedy to remove the rights of citizens to own weapons or to restrict their use, we resist that attempt because of the greater cause of protecting ourselves against an opressive government. It's not only our nature, but our responsibility.
That being said, our homeless population continues to grow and to be a problem and our children continue to be drugged because we do not treat mental illness in a holistic manner or try to understand if a person is a danger to society. We only try to take their guns away or their cars away or some other object they might use carelessly. Our leaders are not going to watchdog our health industry or - most importantly - our drug industry. Has anyone heard about any restriction on Xanex lately? It won't happen. I believe our government will continue their restrictions on objects until we're all writing with crayons.