We are not vigilantes, we are not LEOs. We carry a weapon for only one reason - to defend our life or the life of a loved one. Period.
What do you think being a vigilante means? Vigilantes work outside of the law. It is no more vigilanteism to defend a stranger from a threat than it is to defend a loved one from a threat, something you support.
You may choose to carry a gun only for the purpose of protecting yourself and your loved ones and that is fine as your call, but don't speak for the rest of us.