Hmmm, this is probably the best argument for QWERTY I've seen. It's probably based on relative key taps identifying the keys, so having a keyboard layout that scatters everything makes it easier than a keyboard layout where aoeui are all right next to each other, which are very frequently interchangable between two legal words. Quite a few of the Dvorak consonant clusters are also often interchangable in the same way (crl being the one I have the most, err, "fun" with).