The reason people are paying for training with no job guaranteed is because airlines are no longer funding the cost of training for pilots. People training are putting their life savings on the line to train and then an airline can't even show a bit of faith in the people they are hiring to pay for them to get trained on their fleet of aircraft? I know this isn't unique to BA, but its just a bit galling in the context of IAG reporting massive profits (although coming from a corporate background I can see the difficultly faced in getting investment from those high up in the business).
You also have to admit, a bonded or funded scheme would attract better talent because there is now an additional barrier to people applying.
Of course it would. If BA offers its staff an inflation only pay deal, funded by 'productivity' in these times of record profit, I suspect the chances of a funded scheme are remote!