as17 - you are quite right - fatigue and fitness to fly are major issues with low cost operations - especially Stateside. A few airline managers do not appreciate how FOs are treated and how expensive and even stressful it is to be on standby at a base far away from home.
PJ2 - agree with most of your points but I think we have a trend (rather than a blip) that began with de-regulation and before the recent accidents mentioned.
For the past 30+ years technology has made flying safer even with the increase in fleets and sectors flown. Examples include: TCAS that has improved situational awareness beyond ATC and lookout. Whilst Airbus FBW has enabled all aircrew skill levels to extract the maximum performance from the flight envelope without endangering others.
The big change is the peace dividend (reduction in Military Pilot numbers), access to cheap credit (until 2008) and self selection and pay to fly schemes.
Would that cadets be permitted to use the jump seat and act as a 3rd crew member on EU airline flights - but it rarely happens post 911.