Tony,
Your annecdote is accurate and not a bad thing.   That said, it is the trend that matters.  The trend is for more wealth to be concentrated in fewer hands.   There is no precedent in human history for what is happening today. Keep in mind, with wealth comes power.   

That leads to the second point made by Oxfam, paying taxes.   It would appear that the super wealthy have access to tax efficient holdings (ask Donald Trump for more information) and don't pay thier fair share.  

Concentrating wealth in a few hands who do not pay taxes is not a sustainable model.