If an inmate is in ''protective custody'' why are all of his privileges taken away ?

The area called the SHU or Special Housing Unit is a high security area within a prison used for inmates who may pose a danger to others or be at risk if left in the general population. There is either Administrative Segregation or Disciplinary Segregation. Unfortunately the rules are the same for all inmates in the unit whether you're there awaiting a bed in the satellite camp, for your protection or if you got caught with a cellphone. All of the occupants follow the same protocol as it is strictly run for the safety of the personnel guarding and interacting with the inmates.