If it's 5 people, $100,000, nobody's been waiting more than a month, and you expect a resolution in a month, that's one thing. If it's 250 people, $5,000,000, people have been waiting three months, and you have no idea when there will be a solution, that's a completely different problem.
People are trying to decide whether to trust you with their fortunes and livelihoods. "Some people are having a problem we are working on" doesn't cut it.
You pretty clearly described exactly the situation when money laundering regulations, and the regulations regarding attempted circumvention of money laundering come into effect. MtGox would be in violation (I believe) of most money laundering regulations if suddenly a whole bunch of people withdrew USD with each transaction being a bit under 10,000USD.
As an EDIT: The sort of data you wish you had from MtGox might be secret for a variety of reasons. You could potentially figure out their financial situation, or if someone is really doing something nefarious divulging everything might tip them off, or one could learn scope out their safeguards.
Companies, especially financial ones have plenty of reasons to keep this sort of data secret. Sure they could be in trouble, but everyone knowing that lessens their ability to maybe rectify the situation.