Being a hypocrite does devalue an otherwise good message, because it's a form of "privatizing the gains and socializing the losses."

He expects the cost of sharing wealth and power to be carried by others, despite having more moral responsibility than almost anyone else on the planet to do so, while keeping the benefit of said wealth and power to himself, above and beyond what is justifiable according to his own message.

Hypocrisy fails virtually every moral school of thought. From the moral imperative (Kantian) perspective, if everyone behaves like the Pope, his message has zero results. From the utilitarian perspective, actions matter more than words, and they have zero utility. Hypocrisy means moral bankruptcy, regardless of the message, and is enough to justify summarily dismissing whatever the messenger says, regardless of how good the message it. When that message comes from someone other than the hypocrite, then we'll listen.

It is OK to (metaphorically) shoot the messenger, if the messenger is not delivering the message in good faith.