Earlier quoted context omitted.
So what does that tell about the exchanges that are managed in an unauditable way...
Essentially that they are most likely dipping in to support either their operations or other projects from the customer funds. That's not proof, but I would not at all be surprised if there isn't a single one of them that is clean.
There really aren't a lot of good possibilities here, how did these exchanges get so large before anyone thought of audits?