Because the top ten largest tranches of net compensation aggregates spanned incomes from $20K to $70K in 2009, for example, that's why.
And 8.2 million people in the $35-$40K category had the single largest pile of dough at nearly $310 billion, while the lowest tranche in the top ten were the 3.1 million people who had nearly $211 billion in net compensation and hailed from the $65-$70K category.
All told, over 68 million wage earners in the $20K to $70K category pulled in $2.7 trillion in net compensation, not quite half of the total $5.9 trillion.
The only thing is, the richer have a lot of income which escapes the categorization called net compensation by the federal government, at least another $2.5 trillion. That's how total adjusted gross income for the whole country gets to $8.5 trillion and higher on some 140+ million tax returns.
When it comes to compensation, however, it is the human factor which gives these numbers some life:
73 million people made less than $25K in 2009 (totaling less than $750 billion);
41 million made between $25K and $50K (totaling $1.5 trillion);
19 million made between $50 and $75K (totaling $1.2 trillion);
another 8 million made between $75 and $100K (pulling in together barely $716 billion);
and at the top were 9.5 million people making in excess of $100K. They alone accounted for $1.8 trillion in net compensation in 2009, the single largest sum.
If I were them, I'd try to move the spotlight somewhere else, too.