It comes straight from the Sheik's mouth that EK are not allowed to be delayed on the ground (where fuel burn is least or non-existent). He is also the one blocking inbound ATM and departures slots from DXB. Remember, he sits on the board of EK, DXB CAA and GCAA.
If I may give some free advice to Etihad. Don't go down that road. The company is still young and maybe sanity will prevail. Look at EK's schedule and avoid their times. I can practically guarantee you will get optimum cruising levels to Europe. Same goes for inbounds, profile descent with a straight in approach or a short downwind. Well, most of the time.