Supply Side Economics
This burden is a sum of all their burdens, not just the Federal Income tax. The burden includes (but is not limited to) all Federal, State, and local taxes and fees; the cost of tax compliance and reporting; and the burden of regulators, inspections, and compliance with an ever-changing morass of enigmatic rules. We the people are buckling one-by-one under this burden. Some of us are retiring on pension, some of us retiring early to take pension later, people take partial Social Security at 62 instead of the full amount at 66, many are going on marginally deserved disability, many have moved into the underground economy, many are persuing a life of crime, our children live at home and do not persue employment, and many people are just walking away from employment altogether.
Those in charge either don't recognize what they see or see this as a desirable end.