Public employees enjoy enhanced job rights and protections

Explain why public employees enjoy enhanced job rights and protections. How do these job protections make it difficult for supervisors to motivate and reward the strong performers in their agencies and even harder to eliminate poor and even dysfunctional performers? How would the public service be different if there were no such job protections--other than anti-discrimination laws applicable to all employers--and immediate or higher supervisors could hire, promote and fire at will.