That creates a vicious cycle, wherein the cruelty of disproportionately severe prosecutions drives out those who would not pursue them. When the people with the most convictions and longest sentences for the worst offenses get promoted, whether the criminals deserved them or not, it affects the workplace culture.
Perhaps it would be better to force the state's criminal-court attorneys to spend equal time as prosecutors and as public defenders, and promote based on criteria other than win-loss ratio.