its normally the best position for view of the screen as your head is quite far forward when low in the drops. My garmin edge 705 is the same. i know it doesnt look the fastest but it is the best position for looking at it without taking your eyes off the road in front completely. which is necessary for fast racing.
I think the point was that the computer itself is like an early 90's mobile brick. (Its the Joule isn't it?)
Why put the effort in to get a decent aero profile just so you can blunt it with an object like that or the garmin 705? Thats part of the reason that the garmin team moved to the 500. Its a lot smaller and has (I believe) a better aero profile.
Sometimes decisions in pro cycling are not based on the ultimate performance.
Commercial interests and the desire of scientific measurements have, it seems in this case been the winners, yes if the team had another (more aero) option I am sure they would take it