I had informally considered long haul to be anything out of Europe, but that is just from a UK perspective - and it does of course, make the new Istanbul rail tunnel a long haul operation, together with the Tangier - Algeciras ferry!
Apparently TCX used 3hrs as the cut off between short and mid.
UK govt tax bands for APD start going up outside Europe, so there is some sense in that being seen as an informal boundary, and culturally there are differences between Europe and North Africa / Asia, but I felt just as much of a culture shock arriving in New York! However, for APD, Morocco is part of single European sky, and still 'short haul'.
In terms of travel promotion, long haul implies just that - a heavy, struggling bearing of load! The word 'exotic' might be more appropriate - but it is all relative to perspective. Bali might be an ultimate exotic destination to Europeans or Americans, but is it not just the regional equivalent of Malaga to an Australian, a Japanese or Chinese person?
Just my 2 rupiah.