I could not get a good hold of it, I searched online quite a bit. This must have to do with safety but then non-polarized switches are used through out the world with no issues are risks, so my question why use polarized socket where one blade (neutral) is longer than the other (hot).
The best explanation I came across is, it has to do to with the lamps used in United States where you have to reach out to turn the lamp one and off and may accidentally touch the bulb part which in case of non-polarized socket could either be hot or neutral and can give a shock, but is that the only reason? Somebody could do the wrong wiring and that means you will still get a shock with polarized socket?
I could find other reasons like capacitor between ground and hot wires or making the chases connected to ground etc but I don't think they are the main reasons because again non-polarized switches are used through the world for appliances. So my question is why use polarized switch in the US? If electric lamp is the main reason, why not re-design the lamp and make it safer?