I Think Most Actual Smart People Know This

Rich people are not really the best and brightest by a long-shot.  Particularly when their wealth is related to high finance.  Yes, they are well educated (going to Harvard is more qualification to get into that circle of "elites" than actually knowing/understanding anything), and yes, many are smart at some level.  But they are not nearly as smart as many people (particularly themselves and beltway media) give them credit for.  I think David Atkins take on them is pretty on the money:

They're good at making deals. They know the right people. They have a good knack for social intelligence and little compunction about skimming a lot of money off the top of the labor of others.

That combined with a good dollop of luck and/or a phenomenal amount of greed is about it.

Please note that while it is possible to be ridiculously wealthy without being astonishingly greedy, it is not very common.  In particular any wealthy individual who is complaining about taxes/the deficit/socialism or who supported Romney is definitely greedy.