A Public Defender is an officer of the Court. A defendant is foolish to allow an officer of the Court to represent them in a court of law. As an employee of the Court, the Public Defender is paid to help the prosecuting Attorney convict you of a crime.
In most cases the Public Defender recommends that his client plead guilty to a lesser crime to avoid the possibility of being convicted of a more serious crime,
The vast majority of those accused of a crime will never be convicted by a jury, because they accept a plea bargain. Our prisons are filled with millions of people have never been able to present their case to a jury and in most cases they plead guilty to crimes they didn't commit..