"who failed to contribute as much philanthropically as people would have liked to have seen"
Given some of the stuff coming out after his death, it seems to be more of the case he didn't satisfy people's need to hear about it as opposed to doing it. And since he died very early, we will really never know what the final word would have been.
I guess I would be a horrible billionaire too, since my father taught me it is impolite and improper to brag about giving. I can see why Gates does it (publicity is needed to make his goals), but that is not always the case (and sometimes, it messes up what you try).