On a side note, I wanted to assure our Australian friends that I am really happy for you that you have such a blissful life there (no sarcasm here). Or our friends in any other part of the globe where they enjoy where they are or who they are.
I am aware there are many blissful spots on this planet. The thing is, we can not choose where we are born and, more often than not, where we live. I did not ask to be uprooted from my home town by the events outside my control. I did not ask to be sent to Russia. My choice of Spain came as a result of a coincidence. Move to the States, the same.
The point being, the blissfulness of certain places is a result of many factors, many of which unique, historical or otherwise, which makes it rather difficult to transplant their way of life onto some other place.
If you ask me a hypothetical question, a world without guns or a world where everybody has them, I would chose the one without. But we do not live in a hypothetical world. When you come to America, you can't just cherry-pick what you like about it and discard what you don't. You take the whole package, the good with the bad. America has a gun history. Fought for independence and federation with guns. Survived expansion to the West with guns. Cultivated individualism along the way. Put it (guns) into its Constitution.
Along the way, the same forces that made it #1 superpower economically and militarily (individualism, personal freedoms, and fierce competition), created internal violence and crime. As long as they exist, the need to protect oneself against that violence will remain. You can't have the world superpower with the population consisting of Budist monks.
America is unique (as is Australia, Holland, etc.) and you can't just Frankenstein-ize it by picking healthcare from Canada, gun-control from Japan, etc.