OCU,
re: "but irrespective of how the data was presented, don't you agree that 20% of a country's population controlling 84% of the wealth would appear to indicate that something is wrong?"
Probably. Maybe. I'm not sure. Read on.
What is wealth? I have a feeling that answering your question when we might not even agree on the definition of the word is an exercise in futility.
Three people have the same, decent job. One spends everything on essentials and assets that hold their value. The second spends his money on essentials and equities. The third lives it up and blows all of his excess money (and I know MANY people who live this way). He's got a beautiful house (rented), a great leased vehicle, the latest clothes, awesome vacation photos, and maybe a drug and alcohol problem too.
In 30 years, you've got one multi-millionaire, one guy with significant property holdings, and one guy wondering what he should do since he screwed up and didn't put aside enough for his future.
Which of the first two have wealth? And why do you think they deserve to be punished for making better life choices than person #3?
Is there a problem? Sure, there probably is. But not with the system. The problem is with person #3, who lacked the sense he needed to prepare for his old age needs while he was still young enough to do so.
That doesn't mean that the whole economic system is at fault. At some point, personal accountability for one's own life comes into play.
But I don't think you're a big believer in personal accountability, are you?

Gold is $1,581/oz today. When it hits $2,000, it will be up 26.5%. Let's see how long that takes. - De 3/11/2013 - ANSWER: 7 Years, 5 Months