Unlike america, our internet isn't nearly as well unified, with some regions capable of better connections than others, and some wide areas end up with few internet cables to fight over the service with.
Something a lot of people don't realize is that the World Wide Web, is literally a WEB. Big Cables spread underground through america, canada, germany, everywhere. The ones to places like japan are literally giant wires spanning out underneath the sea. By infrastructure, im basically saying Korea's got a thick, tightly made web... and america's just a long stretched-out flimsy one...
Korea | Rock, Paper, Shotgun here's an article that's a good start on why Korea has it so hax. :3