The difficulty is this is the United States of America with their history, culture and very huge area of open land where you need some form of defence against wild life, including some crazy people. In the context, and that is what we in Britain must consider, of the USA it is sensible and logical to carry arms. When you drive for hundreds of miles through vast areas of open terrority the Second Amendment makes every sense. You are effectively alone without any security but what an American citizen carries in their automobile. They have grown up relying on the gun to defend themselves and their family. They always have done, and no matter what us Europeans think and say, will always do so no matter what.
People living in other vast countries with dangerous wildlife and crazy people seem to manage without having an arsenal in their house.
Canada, Russia, China, Australia, the 'Stans' and various African countries spring to mind.
.. and specifically, I wonder what you're likely to encounter that requires a firearm when you're at School.
A nutter who comes in to shoot up the school, and that is how Americans think.
Like it or not, and I certainly do not like it, that is the reality of the USA. You can make comparisons, discuss moral ideals, and advise from a far on what Americans should do, but it makes damn all difference. It is their nature for all the reasons I suggested, and probably more like their amazing insecurity that I have noted on many occasions over the years.
I always recall the incident my husband and family almost got involved in outside JFK Airport, New York. A white redneck objected to a black man taking his place on an a overcrowded hotel bus and without hesitation produced a handgun and said "If you get on that bus you fxxking nxxxxr I'll fxxking shoot you!!" He meant every word. That is how easy it is for the gun to be of second nature in any confrontation. I have seen other examples in the USA, which my ex-military American friends were horrified about, but they just said this is the United States of America and this is what our society is. They did not possess guns even though they were fully trained to use them, but they were resigned to the status quo.
After all that though I LOVE the USA, and would live in Colorado like tomorrow. So envious of Guffer!