This might come as a shock to some posters... have you seen the three little letters that BA put after their name on their letterheads?
plc.
It means they have shareholders to satisfy, and will therefore act to make a return for them. It may be that it does this in such a way as to make regional services unprofitable for them; that is their model.
But to say that they have to provide a service to the whole nation if they are to carry the moniker "British" is just plain daft. You could equally argue that Brussels Airlines should refuse your money if you live in Antwerp....
TA