HZ123:
Those overseas carriers that you quote are I believe to be chapter 11 or in serious debts even with UK airport charges as minimal to encourage them.
Chapter 11 provision covers US airlines only, although similar provisions exist in Canada.
Almost every US transatlantic carrier is in the brown and pungent for a number of reasons that are well covered elsewhere,so let's leave them to one side (even though they have continued to operate their existing MAN schedules and the Asian carriers continue to suffer the impact of SARS, unlike the US carriers).
This still leaves Pakistan International, Singapore Airlines, Malaysian Airlines, Emirates, Qatar Airways, Air Jamaica and BWIA (if only in name) all willing and able to do what BA are apparently unwilling and/or unable to do - ie, operate long-haul flights from UK regional airports.
There
has to be a reason for this, whatever the reason actually is.