But to kill yourself all you need to do is reverse, blades running over that live power cord laying in the grass that you were too lazy / stupid to at least turn off before mowing.
To injure others you simply need to run over the air line you used to blow up your tyres and again were too lazy to replace & turn off the compressor.
Creationists firmly believe you can legislate out stupidity.
War mongers want lots of idiots available for cannon fodder should the need arise so they want to stop them killing themselves before hand.