Besides for sports, etc., The two reasons for owning a gun is to commit crimes and for protection. How can a person feel safe in their home without a firearm in case some nut breaks in in this day and age. Criminal paradise when citizens are unarmed. When a person wants to commit a crime with a gun, he will find an illegal one if they are outlawed.
Problem is that risk of injury with guns in every house is greater than the chance of an occasional intruder. Same goes for carrying legal guns. More deaths if everyone had a legal gun. The risk is greater because there are more guns. Safer for law enforcement when everyone they encounter with a gun is a criminal. No problem to kill someone with a gun because they are criminal for having a gun to begin with.