a) your charts are a classical example of "try hard enough and you will find 2 charts that correlate"

b) Inflation affects the poor because they don't, and sometimes can't, hold assets that traditionally protects the rich from inflation, such as real hard assets (such as real estate) and a sizeable chunk of stocks (some types) and bonds (TIPS and short duration). The poor lives paycheck to paycheck and see their income staying the same while everything else around them is increasing in price.