It was because of the speed of procesors available then. It was didcovered that most typists then type in words faster than the processors could handle then. To solve this problem, a man came up with a layout called QWERTY.
This was later changed as we have faster processors by a man called DVORAK. He made this layout after his name. But this not popular as peoplehave become used to the QWERTY format.
However, you can change your keyboard layout to whatever you think is more suitable for you. You can set that from your control panel.