The Stratocaster design was conceived to address issues with the Telecaster design - uncomfortable body edges and balance - as well as issues with Bigsby and other vibrato systems available at the time. Plus having the switch and controls in easy reach. Not many.people seem to note that the angled hole for the arm allows for the guitar to be put into the case without having to remove the arm. Just swing it round to the forearm contour and it's low enough to close the case. A lot of people take the arm out before putting the guitar in the case and then the little tension spring inside the hole falls out.