I believe it is because the arrangement of the first six letters in the top alphabet row of a standard keyboard QWERTY goes way back. The layout was created in 1873 when Christopher Latham Sholes made improvements to his earlier typewriter models in order to design a quicker and more efficient typewriter for E. Remington and Sons.
The standard QWERTY layout keyboard is called 'QWERTY' because on the top line of the keyboard the first 6 letters from chronological left to right order are; Q, W, E, R, T, and Y.
Or...if you're wondering why it's QWERTY and not ABCDEF, it's because when typing with the alphabetical format, many of the keys would clash with each other due to the arrangement of keys on the original typewriter. The QWERTY layout became so popular, it was the standardized layout for typewriters, and even keyboards today.
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