Well, the right to bear arms in the US kinda also stems from the fact that;
1. You guys had just overthrown your lawful government because the King wasn't cool no more.
2. With no real standing army and facing a war, plus the likelihood of further armed conflict down the road, the right to bear arms was as much about freedoms as it was a means for civil defense since the militias played a huge role in fighting off the Brits.
Add in the fact that the armed forces were in their infancy, the distance between places and that the fastest mode of travel was by horseback, and suddenly letting every home owner stockpile guns isn't such a bad idea! (especially when your home is being invaded by unfriendly foreign forces)
3. North American wildlife is still very, very angry and tends to think of you as a instant all-you-maul&eat buffet!
Do we honestly need the age-old right to bear arms as it was intended back in the day? Probably not, but after being there for going on 3 centuries, the massive population explosion and modern production, it's pretty much impossible to remove all the guns from the US now.
Besides, amending the constitution and removing that right still won't stop gun violence, especially from the criminal aspect... those bad guys who are already ignoring the law to commit crimes are still just as likely to go and get their illegal guns.
Maybe that's why they're criminals?!