well "ignorance" pretty much sums it up. If we didn't draw it out in color pictures or put it on a movie people wouldn't do what they are supposed to or do what they are not supposed to do.
If we didn't have training we would have idiots out there working with no safety glasses with a grinder in their hands chopping away on a piece of steel with the electrical cord laying over top of where they are cutting. The outcomes would not be good.
Safety training is money and time well spent.