Having a very health and prosperous society, rates of pony on pony violence and violations of the NAP are quite low. However, they are a prey species who do tend to live in rural and frontier areas, and as such being armed in order to fend off both invaders as well as predators is probably not uncommon. I don't see their culture being pacifistic. We know the Equestrian state has a standing military; I don't see why they wouldn't have civilian militias as well.
This is ignoring that Equestria in the show hasn't reached the technological level needed to reliably mass manufacture firearms.