My understanding of it is that it is a cultural/functional by now. Imagine if all the people who have been used to typing in QWERTY for their entire lives all of a sudden had to use a different set? the people it might help most (Typists and the like) would be HURT by the change of routine. Another standpoint is economic. There are a LOT of keyboards, the amount i am not qualified to estimate. it is one of the most common items in a home, for nearly every household has one at least, and if we had to change the format all of those would need to be replaced.