A lot of people with high IQs may also be very rational / logical in their approach towards life. They might think objectively, and that's the point. They're right - they don't need the excess wealth at all. They've accounted for everything they needed to - their life, their security, and that of their children, spouse, parents, etc. They're for the most part content with their personal lives, their success, their jobs and most importantly their income. They're I assume, smart enough to know what could make them more money, and how they need to behave and interact. It's not ignorance; it's sheer conscious choices.
On the other hand, there are those who aren't smart / wise enough. They'll make much more money, but may not be as nearly satisfied, no matter how much they make.
We might be mistaking intelligence / business-sense with wisdom, which is a higher domain - it's got more to it, than just IQ.