Yes, agreed with Sociologist, In sociology its better described by fulfillment of basic and social needs, In psychology almost the same thing is described by theory self actualization. The process or feeling in your self that you have done full according to your potential, or you have fulfilled your potential.

One problem in Pakistan is that most people don't follow their potential or talent in studies and hence in profession mostly they follow social pressure (unconsciously). This social pressure makes us biased in selecting our profession. And this is best visible when we come to know that about 99.99 % students of pre-medical who get marks 900 plus do apply for Medical college. Do they all have interest or talent in Medical, nopes its just social pressure, created by social status given to Doctors, and by peers and friends.
Apart from self actualization this social pressure too brings people to CSS.

And there may be also some cases for whom CSS is for fulfilling their basic needs (may be they dont have interest and talent for CSS job but they feel its the most likely place where they can get a job and yes with due respect as well)

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"The only necessary thing for the triumph of evil is for good men to do nothing."
--Edmund Burke (1729-1797)