I'm in the UK, how have I been protected from illegal firearms for over 50 years? Do Americans think adequate firearm regulations and reduced incidents would happen overnight if say a UK system was brought in? It takes generations.
If you were brought up in a culture where you locked your firearm away when not in use, you don't carry and/or use a gun in public, and you go through a meaningful wide ranging background check, your orientation towards guns will be totally different.
Owning a gun is down to the person in the UK, if they've led a life to make themselves unsuitable, they can only blame themselves. Orientation to firearms is cultural, probably most to all Americans wouldn't pass a UK firearm application.