The leadership of NTSB and many other investigative bodies around the world are political appointees with usually no hands-on experience with aviation, railroads, shipping, or trucking. They depend on their highly experienced technical staff to dig out the data, but draw the final conclusions themselves. It sometimes happens that they override the recommendations of staff when they are idealogically unpalatable. Notably they have been sometimes reluctant in the past to acknowledge management actions or human physiology or psychology as contributing factors in accident scenarios, preferring to hold operating crew members to superhuman levels of perfection, regardless of circumstances. It's easier and less professionally risky to blame the individual rather than the system. The company, the unions, the various government agencies, the equipment manufacturers, and in many cases the victims, all have their representitives on hand to "aid" in the investigation and "provide expertise", but really to defend their organization's interests and shift the blame on someone else.
Doesn't it just warm the cockles of your heart?
Cheers,
Wes