OttoVB,
Understand that fully, unfortunately the company financial department at BA doesn't! Those that did provision for their retirement at 55 suddenly found that the pension they relied upon was worth less that half of its projected value. Due to insufficient investment by the company leading to the infamous 'Pension deficit with an airline attached' headline. The 'rescue' package is painful to swallow and basically means that most pilots will have to work at least 5 years longer with most 8-10 years longer to re-coup their original pension.
Hence the reason for many to go beyond 55. It's not greed, it just goes back to BA's lack of investment in the pension fund.