After graduation( 16 years) or master degree, many students have financial problems in their home. In facilities all students cannot be equal. There is a huge difference between one who is studying for 18 hours daily with minimum social and financial problems and for one who is working in private or government deptt with continuation of css study. And you know well the css is a competitive exam. so one should be given maximum opportunity and chances. also it is the exam of perseverance. if one can give css repeatedly, it means he has more and more perseverance.