This is about money. It always has been and always will be. The professional activists and lawyers are following a tried-and-true MO: demand that this Inquiry (like previous ones) be expanded in scope and scale and length to the greatest degree possible and to pay as many exorbitant fees to as many people as possible, for as long as possible, for their participation in it. Ideally for them, the Inquiry would evolve into a perpetual quasi-welfare program that has as vague and broad a mandate as possible, no end date, and a blank cheque for a budget signed by federal leaders that are so scared of the identity-political backlash that they will pay literally hundreds of millions of your tax dollars to placate those who demand it. 

Money is at the root of all of this. People want to be paid more, for longer. More people want on the gravy train while the going is good. That's why people are quitting the commissions. They came to the realization of what is really happening with this inquiry.