I have worked in a major airline and also within the air charter industry for almost 30 years and have only seen one pilot call in fatigued. Upon management hearing of this they contacted the pilot, not to check on his welfare etc. but to talk him into doing the flight. From what I have seen the problem with fatigue management in aviation is the management of the various companies. Many don't think that it is serious and think that it is the pilot screwing them or just think it's a crock of sh!t.
I'm now in a different industry in a large company and they don't just talk about fatigue, but have measures in place to manage it. I've also seen staff call in fatigued and this will delay a trip, but from what I have seen there is no adverse repercussions from management. The big difference between the industry I'm in now and aviation is that the management can be held liable if there is an accident due to fatigue and rosters, management decisions/pressure etc. are the cause of the fatigue.