This is a social evolution sort of a thing: if you are a zealot and you know how to spend money to effect the change you want, then you aren't going to stay on the money-accumulation train for anywhere near as long. You'll spend it, and make some of that change happen.
You need something like this sort of effect to explain why there are any wealthy people at all. Any one of the Forbes 100 could cure a couple of diseases, get a fair way to demonstrating a cure for aging in mice ($1 billion price tag), develop the tech to irrigate the Sahara, etc, etc. But they largely do not, and remain within the process they have built for themselves. Where they do go all out for philanthropy, there is usually a startling lack of imagination - see the Gates Foundation, for example, which is doing nothing more than business as usual in big philanthropy, or the Ellison Medical Foundation which does nothing more than replicate the NIH.
Anyway. Knowing how to spend money "right" (meaning right for you, your vision, having a vision, etc) is not compatible with accumulating money, and only the outliers will fall into both camps.
http://www.fightaging.org/archives/2012/02/one-wealthy-zealo...