A full explanation would take volumes and I'd no doubt get things tangled up, but as I recall, Mike wanted to pursue other ideas. Remember, he and Charlie Conrad had developed the concept that led to the first issued patent. Mike had been forced into the top job upon the death of Lawrence Mealey. Lawrence was indeed an internationally known and respected (sometimes hated) top executive.
Mike has an IQ that is somewhere in the stratosphere and he just doesn't think like most of us. He also is not the type to be tied to a desk and a position that requires budgeting and all of the politically correct words and deeds. I think he fully understands and accepts his limitations. Also, Mike just isn't consumed with things like money.
There were some other considerations in him naming both Malcolm and Lawrence to their jobs, but they probably are best not addressed herein.
Hope that helps.