Rat 5
I hea what you're saying, and to a large degree agree with your points. The problem comes when you try and balance the working patterns of homo sapiens. Striking a balance between earlies and lates is a near impossible task when you consider the differences between people. Some on this thread have said that they would prefer to do earlies, some prefer lates. Trying to write a legally enforcable document that catered for a host of individuals preferences would keep Bodgitt Leggit & Scarper, Barristers-At-Law, in business for many, many years.
I've worked for airlines that tried to introduce preferential rostering around earlies and lates and it was not easy. We found that, after a period of approx 3 months, most of the crews were unhappy about their patterns and reported they felt more likely to suffer from fatigue, although nobody actually reported they were fatigued.
The fundamental problem with crew scheduling at the moment boils down to airport capacities, IMHO. More and more flights are being scheduled at 0500-0700 local because of runway slot availability (or lack of). Because of this, the first duty in a series immediately triggers a limitation factor, either start time after days off or early starts. Once that limitation has been triggered it doesn't take long before the limits are reached and the roster flow suffers as a result.