Where do you think the evil doers get their guns?
If you have a nation in which there are sufficient guns in circulation such that every man, woman and child could have one it means that there is a much higher
probability that guns will be stolen or misplaced or otherwise get into the hands of people who want to do harm.
This is why the sheer number of guns in our society becomes a problem. MORE GUNS = higher probability of guns making it into the hands of those who wish to do harm.
As for people being able to defend themselves: well that's a noble ideal and certainly one that would be nice. But the fact of the matter is study after study after study shows that guns kept in the home
are far more likely to be used against people in that same home (murders, suicides, etc.) and few guns are actually utilized in terms of "self defense"
From
THIS SOURCE:
9-10. Few criminals are shot by decent law-abiding citizens
Using data from surveys of detainees in six jails from around the nation, we worked with a prison physician to determine whether criminals seek hospital medical care when they are shot. Criminals almost always go to the hospital when they are shot. To believe fully the claims of millions of self-defense gun uses each year would mean believing that decent law-abiding citizens shot hundreds of thousands of criminals. But the data from emergency departments belie this claim, unless hundreds of thousands of wounded criminals are afraid to seek medical care. But virtually all criminals who have been shot went to the hospital, and can describe in detail what happened there.
May, John P; Hemenway, David. Oen, Roger; Pitts, Khalid R. Medical Care Solicitation by Criminals with Gunshot Wound Injuries: A Survey of Washington DC Jail Detainees. Journal of Trauma. 2000; 48:130-132.
May, John P; Hemenway, David. Do Criminals Go to the Hospital When They are Shot? Injury Prevention. 2002; 8:236-238.
11. Self-defense gun use is rare and not more effective at preventing injury than other protective actions
Victims use guns in less than 1% of contact crimes, and women never use guns to protect themselves against sexual assault (in more than 300 cases). Victims using a gun were no less likely to be injured after taking protective action than victims using other forms of protective action. Compared to other protective actions, the National Crime Victimization Surveys provide little evidence that self-defense gun use is uniquely beneficial in reducing the likelihood of injury or property loss.
This article helps provide accurate information concerning self-defense gun use. It shows that many of the claims about the benefits of gun ownership are largely myths.
Hemenway D, Solnick SJ. The epidemiology of self-defense gun use: Evidence from the National Crime Victimization Surveys 2007-2011. Preventive Medicine. 2015; 79: 22-27.