BA's longhaul seats/service may be good but that clearly isn't enough for somebody wanting to fly from/to one of the many places OW doesn't cover sufficiently!
Edited to add: And remember that BA offers what probably is the least convenient hub in Europe; the overcrowded, zoo-like LHR and, for the few that can put up with LHR, has in store the LGW/LHR switch for extra enjoyment.