...there is plenty of independent experts on the board, so why all the continuing clamour for the data to be released?
For the same reason intelligent educated parents take their children to quacks when medical science fails them. We believe there is an answer to everything and for some people the "wrong" answer is better than no answer.
Not too long ago we would have blamed gods for such a mysterious disappearance.
I believe they will find the plane, whether there's anything approaching a widely-accepted explanation is another matter.