"...bonus criteria so low this year that they would have made money even if the company had made a loss..."
Errrrmmmm, I think you've missed something. The industry is in a terrible state. I don't know about EasyJet's accounts so I can't be specific, but for many airlines the best they can possibly hope for is minimising loss. Management bonuses are intended to reward the management for performing well. If their best possible performance still results in a loss then bonuses despite making a loss would be entirely reasonable.
Argue if you will against bonuses, a reasoned case can be made. Make a case if you can that EasyJet should be in profit so a loss is down to poor management. Make another case that management is poor and should not be rewarded. Don't just assume that a loss should mean existing bonuses should not be triggered.