ability to use a knife, a crowbar, a bottle, a fist or whatever is not a reason not to limit access to guns and ammunition ...
Well, actually it is, because firearms would be a good method to defend yourself from such attacks.
Mind you, I am not a proponent of firearms for the public, I live in a country with guncontrol which for our culture and background is probably the right choice. Problem in our country seems to be that most shootings are executed by armypersonel with PTSD. This of course makes the discussion about guncontrol that much harder.
Note that even for armypersonel or police forces, gun ownership still has all kinds of restrictions. Toddlers inadvertently shooting their siblings is not something that could happen here.