Whilst I agree with the thrust of your argument S1E, on a point of order it is worth mentioning that the most recent development in the retrenchment of SQ at MAN was actually to upgrade the service to daily as of this week!
Wanna_be_there: argument from the last century unfortunately. In the 21st century the country of origin of an airline is increasingly immaterial - ie RYR, EZY, AF, LH etc either with multiple non-domestic bases, or foreign subsidiaries, and that will only increase.
As the BA JFK flight demonstrated, a long haul base with a single daily flight will only ever have a shaky future at best, unless it can be ramped up to start to achieve a critical mass of daily flights. A long term plan, the resources to cope with 2-3 years of losses as traffic built up, and properly based crews would be an absolute minimum starting point, and I can't see BA being in a position to do that anytime soon even if they had the inclination.
The best chance of BA returning might be if they decided to partner with a new start up airline, which would have none of the overheads that BA have. Something along the lines of the model they used to have with GB Airways might work, as long as the start up had very deep pockets for the start up costs (we're probably talking 9 figure sums), but I won't be holding my breath!