Well I think, they check what availability have customers which want to travel to Thailand?
From Europe there is not much better then themselve !
LH, BA, AF, are around the same, LX may be is a litle better and OS, KL SK ,AZ even don't offer a first class.
Between the USA and Thailand is not that much competition, and most US carriers are more than 3rd. world in point of service.
So the only competitors come from Asia SQ, CX and may be EK !
But who ( from Europe, Australia ) want's to fly via SIN/HKG ? The price is higher, it takes at least 4 h. longer and the incovinience to have one more stop. May be from the near east market, they have a real competitor with EK, but there they seem to be no big number. They fly daily once with an old airbus 220 seats and EK 3 times with it's newes equipment 77W at least 1000 seats daily.