There is no basis for comparing the salaries of Govt and those in private sector. Look at the size of the Govt workforce. It is around 4.5 million (45 lakhs). The largest employer in private sector is TCS which is barely a lakh. Any hike has to factor this huge mammoth size of workforce.
In private sector a major part of salary is variable and linked to the company profitablity. It can go up or come down. Such a system cannot be implemented in Govt.
In private sector Hire and Fire policy is there so if company fortune dips one can be thrown out, but in govt employement is guaranteed. This guarantee is should also be counted as an incentive in case of govt employee's.