What's wrong with our outlets? We've got less voltage, and a ground plug that makes contact first. When the outlet is in a room with water, or outdoors, it goes through a ground fault interrupter to keep people from being electrocuted.

We reserve 220 volt outlets and higher voltages (3 phase 480, etc) for the larger loads, and those plugs are huge, and not something found in a typical home.

While this is all true, less voltage comes with a price and that is more current.

2 times less voltage === 4 times more heating for the same resistance (heating is calculated from R times I^2).

This means that short circuits, wiring problems are potentially much dangerous.