Reading the comments again, by "making money" I did not mean earning money like the crazy guy still having an income from assets he acquired in the past, but be

Reading the comments again, by "making money" I did not mean earning money like the crazy guy still having an income from assets he acquired in the past, but being able to make new deals, start successful companies and so on. But I understand what you mean. I disagree that "rich people becoming out of touch/crazy" is as likely as you make it sound. But of course it is possible. Nevertheless, usually there is only the track record of their past to evaluate a persons authority. You can add a small discount for "may have gone crazy", and of course attribute the luck factor, but that's it.