On our flights from South east Asia to Europe, we stop off in either Dubai or Abu Dhabi. On the P.A. during descent in the Middle east I always say " While we're in DXB / AUH, we will be asking you to disembark. This will give us the chance to refuel, re cater and clean the aircraft. It will give you the chance to stretch your legs,get some exercise do some duty free shopping ......."
The number of passengers, especially those who would be considered 'likely candidates' for DVT (old / overweight), sitting in EY who refuse to disembark and insist on sitting down for the 8 hours into DXB the 1 hour transit, then the 8 hours to LHR, is staggering.
Fear of getting lost in the Terminal and missing the onwards flight is usually the reason given.
I wonder if laziness is the real reason though.