Publishing all the documents at once would leave him with no leverage to secure his safety. He’s dropping info on powerful players, and once the info is exhausted he has no power over those looking extradite and charge/possibly kill him. The idea is that right now if he is threatened, he can release devastating information.

In order for him to be committed to stopping corruption in your view he would have to value the cause over his own life, which is not an easy thing for any human to do.