ultra long haul flying means that your (and the other 349 passengers) crotch, armpits and mouth have a nice chance to really marinade, before disembarking the aircraft, 14 hours, and several time zones, later.
severe weather can cause "unexpected delays". so can twerpy ground crew who drive their luggage trolleys underneath the wing (instead of around those rather inconspicuous orange cones), and rip off a chunk of the plane.
transiting abu dhabi airport -and it's unrelenting P.A. system- for half a day, is guaranteed to match every sleep deprived itinerant in the terminal's arabic language skills with those of a foreign service officer (rosetta stone certainly doesn't come with a bottle of duty-free glenfiddich single malt).
and by law, every flight over 6 hours must provide passengers with carbonated beverages, in-flight entertainment, and a cabin full of screaming 2 year olds.