Philip Greenspun makes a compelling argument that the new pilots making $25k and working the longest hours under the worst condition is a desired side-effect of union negotiations. The senior pilots, controlling the union and thus its negotiating policy, improve their outcome as much as possible. The junior employees are only nominally represented by the union, and their welfare is not a objective of the negotiations.

Source: http://philip.greenspun.com/flying/unions-and-airlines