I know a lot of people from a lot of different walks of life from all over America that do own guns. I can safely say not one of them do so that they can form a militia.
People watch the news and see a bunch of hillbillies in oregon, and listen to the NRA and think that is the typical American gun owner. Well its not.
You also have
hobbiests (yes its hard to believe some people just like guns)
Hunters.
People who have them for protection (from people or animals or both)
Gangs (big and small. I don't think they are trying to form militias)
So while the second amendment may be used to protect peoples rights to have guns based on an age old american principle, its probably the last reason most people own guns. People from the the UK and Canada and Australia are so terrified of us and our craaaaazy gun laws. Stay home. America is just to scary for you. You are better off arm chair quarterbacking from the safety of your home.
*wildly shoots guns in air screaming yeeha merica!*