In 2006, Congress passed a law which required the USPS to fund _75 years_ worth of employee pensions in advance.
You wanna talk about taxes being wasted? Go look at Congress; they've been trying to kill the USPS for years.
It's like asking if a family can live on $50k a year but then stipulating that oh by the way in this family the father gambles 90% of his earnings away at the casino on payday. It doesn't really answer the question.