why the rich don't give to charity

Today I read an interesting article from the Atlantic looking at the disparity in charitable giving between the wealthiest Americas (the top 20%) and the poorest (the bottom 20%) in terms of percentage of income—1.3% vs. 3.23% respectively. In particular, the article notes that while lower-income Americans are presumably no more intrinsically generous than anyone else, "some experts have speculated that the wealthy may be less generous—that the personal drive to accumulate wealth may be inconsistent with the idea of communal support."

If true, I think part of the reason may be due to the logic of what Marx called the 'coercive laws of competition,' which compel capitalists to accumulate capital; and this systematic drive, much like the personal drive to accumulate wealth, may be inconsistent with the idea of communal support. The working class and poor, on the other, are not only more exposed to, and familiar with, privation, but they're predominately compelled by the ever-pressing need of acquiring their means of subsistence rather than the drive to accumulate capital/personal wealth, giving them a greater feeling of solidarity with those struggling to get by and encouraging them to give more in terms of percentage of income even though they have less to give.