WB3 - you are correct. It is proven that the more safety nets you place, the more lax people get. The net gain in safety is less or nil. You will never make stupid people smart, you can only protect yourself from their stupidity.
I heard the same kind of argument for round-about intersections: They are more confusing so the driver has a heightened sense of awareness, therefore they are safer - WHAT? Confusing the driver makes him safer?
I try to be very aware when I use a saw - keep to the side, one finger on the table, etc. One day I turned off my saw and bent down to pick up a pen I dropped. Suddenly realized my head was about 1" from the still spinning blade. I froze til it stopped. It would have stopped no more than 1/8" into my skull, but it still woulda sucked. One moment of distraction....