Another possible answer to the "What's in it for him?" question:

The Everest effect.

George Mallory: "The first question you will ask, and the one I have to answer is, 'What's the point of climbing Mount Everest?' And my answer should be, 'It's no use.' There is not the slightest prospect of any gain. Oh, maybe we can learn a little about the behavior of the human body at height, and medicine can change our observations for aviation purposes. But nothing else could come of it. We will not bring back a little gold or silver or gemstones or coal or iron. We will not find soil or earth that we can grow crops that produce food. There is no point. So if you can't understand that there's something in humans that responds to the challenges of this mountain and goes to meet those challenges, then the struggle that ensues is a struggle from life itself upwards, and you won't see why we're leaving. What we get from this adventure is just joy. We don't live to eat and make money. We eat and make money to enjoy life. That is the meaning of life and the purpose of living."

Why generate all of these papers? Because, for the first time, he can.

Doesn't have to be for the money or fame or potential for speaking engagements. It could simply be that he wants to test the limits of what's possible.