I know a lot of the discussion on this thread has been about *A airlines, but it happens elsewhere too.
BA is currently ‘investing’ in ‘improving’ its IT. One of the consequences is, as has been discussed on this thread, it is now not as easy as it was previous to the ‘improvements’ to find fare classes on BA bookings.
IMHO all of the airlines are trying to simplify (or rather, dumb down) their IT, which might make it easier for some customers, but not for others.