we do have to do a better job at making sure these guns are not so damn easy to come by!
And this is what the argument boils down to.
Some say that making the guns illegal makes them harder, but not impossible, to come by. Making the "crime of passion" multiple shooting like Sandy Hook much more difficult in that it would require advance planning on the part of the nutcase (something that most nut bags aren't good at)
Others are unwilling to compromise on the existing situation, basically saying that the risk is worth it.