Most people know not to leave a loaded gun lying around. It is an unfortunate fact that some don't but the question is do we enact laws that will restrict everyone from exercising a right because of what a few careless people do?
Yup. Because there's no good reason for you to have a gun to start with.
One more time-
We banned lawn darts after a few deaths.
We put safety films on pills after one poisoning incident.
We have 33,000 gun deaths a year, and guns are still legal.
What's wrong with this picture?