The OP raised a valid point and it's triggered off some interesting responses.

I remember being a bit surprised once when my wife and I had separate but concurrent flights from LHR to Tokyo, her flight (Virgin) was non-stop and I was Swiss flying via ZUR.
I expected a shorter leg from Zurich - ( it's east of London and nearer japan, I thought)
Turned out that the flight paths mileage LHR-NRT was about 10 kilometres different from that of ZUR-NRT