I'm glad you qualified and explained your question as this question often spurs vigorous debate.
The cards I pass out when asked why I Open Carry state:
1) Personal Safety - Because I take personal responsibility for my own safety and the safety of my family.
2) Community Safety - Because I believe that my community is more secure when its citizens are prepared to defend it.
3) Liberty - Because it is an affirmation of my Federal and State Constitutional rights, as a free, responsible, law abiding member of society.
4) Activism - Because we must exercise our rights or we risk losing them.
5) Community Education - Because the general public must be conditioned to accept open carry as normal, as it is my right.
I believe that one of the biggest reasons there is such paranoia over guns is because the masses have been socially conditioned to think that only criminals or police carry guns. The most effective was to counter this conditioning is to openly show that guns are simply tools that in and of themselves have no propensity for good or evil.
When I hear the argument that easing restrictions on firearms will turn us back into the "old west" with gunfights in the streets, I remind them that the "old west" was all in all a very polite society where rapes and muggings were rare largely because most men and many women were armed and prepared to defend themselves, their property and their loved ones.
I also suggest that gun owners take a few minutes to read this scholarly analysis:
A Psychiatrist explains "Raging Against Self Defense" (Why gun prohibitionists act the way they do) -- an essay by Sarah Thompson, M.D.