Some of the signatories call for his resignation.
The problem here is that the producers of drupal are a much smaller set of people than the consumers of something like drupal. It's the consumers that will have to decide whether they want to base their next project on Drupal or not and all this infighting is giving of an aura of extreme instability. So as a result the drupal project as a whole will suffer because some fraction of that audience will decide to move on from Drupal.
I might agree with you if it were a call to resign or similar, but they aim at getting (to them very relevant) information that has been demanded in public (and I have to assume in private as well) before, without result, not necessarily at a reversal of the decision.