HZ
I'd venture the proposition that the chances of BA pilots crewing DHL aeroplanes are somewhere between zero and fcuk all. It is hardly as if DHL is taking any jobs away from BA is it? Rather BAWC saw an oppertunity and siezed it. Since BA don't operate short/medium range freighters, they chartered them in. BAWC and DHL stand to make a profit from this business, and now you advocate jeopardizing it because the aeroplanes are not flown by Nigels? Jeeezzzz ....... As Neil hinted at, if BA had a fleet of freighters then you would have a case. They don't, and neither do you.
The thing is, BA needs freighters. DHL does not need a, comparatively, minor company like BA. It's a nice little business that'll keep the aeroplanes busy at off-peak hours, and generate a profit, but that's about it.