Having read the thread through re BA, I can only comment on their daily flight from LGW to RIX and back again.
That flight is usually about 80% booked, both business class and cattle class. If such an out-of-the-way place like Riga has 80% booking, where, oh where, are they going wrong?
The only competition BA has flying to London out of this city is a BT-SK connection out of Copenhagen (pretty much the same price, mind you) but it takes three hours longer.
I always thought that if you had more than a 55% payload you were making money. At 80% this short-haul operation definitely is making money for BA. So, if they go long-haul only, they will lose income by eliminating RIX. In that case someone else will come in and make money.