With gas price up up and up, why would any airline followed these stupid path that waste fuel??? divito talked about the flight path was set and everyone just follows, so who the freak set the path??? If human just follow what was set before them, then we are not better than monkey or kangaroo.
You're asking who devised following the directions of north, south, east and west? Er...
People found that following a compass pointing to a certain area had them arrive at a certain location. Once this was mapped out, people were taught and knew that going "this" way would get them to "this" place.
Why would they follow these "stupid" paths that waste fuel? Simply because going any other direction under what they've been taught would not seem to make any sense to them.