The voters do have a say. The voters can influence who is the head of it. This control is indirect. The Postmaster General is selected and appointed by the Boa

The voters do have a say. The voters can influence who is the head of it. This control is indirect. The Postmaster General is selected and appointed by the Board of Governors of the Postal Service. The members of the Board of Governors is appointed by the president, with a seven year term. No more than 5 of the 9 governors may be from the same party. The president cannot fire or force a governor to resign. This is far different than what you want, which is to have the president be able to replace anyone in an important position. If you want everyone to vote for everything, move to Switzerland where there is a direct democracy. If you want the president to be able to replace anyone in an important position, move to some place with a dictatorship.