I think a major contributor to Longhaul SFO's not bidding for Shorthaul command has to be the NAPS pension issues (and thats not BA's doing it's the Government's).....
Why would you become a shorthaul captain to create a ~£300,000-350,000 pension liability (i.e. you OWE THE GOVERNMENT).... BA Pensions pay this to the Gov but then charge you MPF rate (currently around 9-9.5% interest PER ANNUM) on this figure.....
If you've got 20+ years to retirement that could virtually WIPE OUT your entire pension!
And no I'm not being melodramatic... the figures are out there!