Every pyramid scheme reaches a point where its organizer grabs the rest of money and vanishes.
If the organizer made a lot of deposits early on he wants more deposits to get more profit
I think what you are saying is still basically right, they are anonymous, usually not great people and there is a lot of money available so they tend to steal it
makeBTC has been paying everyone and taking care of all problems so he seems to be aiming for a long term profit instead of a small quick gain