Statistically speaking, guns are used in more crime prevention incidents per year than in committing of a crime. This is a fact according to the majority of studies except a single statistical outlier study that is frequently quoted by anti-gun groups.
Classifying violence based on the instrument of choice used by perpetrators of a violent act rather than based on the psychosocial factors that cause high levels of violence is nonsensical. Would you similarly suggest that violence in the form of suicide bombings is high in some Muslim countries because fertilizer and other explosive components are prevalent and easily accessible? I would hope not.