You mistake for competence his greed and that of those who surround him. I don't think there was a plan to profit from the disaster; rather, they're so incompetent that they even lack the basic self-control to avoid publicly taking advantage of the mess they unwillingly caused, however bad and dangerous that might be.
I imagine Trump wanted to do some fun new things when he is old and will soon die. Its not many who get to experience what it feels like to start a war and kill world leaders, and when you are gonna die soon anyway why not?