Sure, three-pronged plugs can be quite annoying, especially when you're used to regular ones that only has two pins.
But before grabbing those pliers and chopping off that extra rod, you ought to know that that might just save your life.
Called the "ground," it shouldn't be removed for safety reasons. If there is a failure in the appliance with this type of plug, the third pin, which also reduces electrical noise, will create a short circuit and blow the breaker or fuse.
Without this to turn off the power on the short-circuited device, the current will electrocute the user.
Here's a quick video on the difference between the two-prong and three-prong plug:
But why do other devices lack the ground prong?
Since some companies find it expensive to add the third pin, a plastic outer casing or other non-conductive material for two-pronged electronic equipment are cheaper alternatives. Devices that don't use much power (razors, cellphones) also have the standard number of prongs.