In your opinion what are the reasons for attitude of a government employee being radically different from a private sector employee?

A Government Employee enjoy more Job Security and Regular Life Time  Income. Promotions are optional and Seniority counts more than your personal skills/achievements/education.

A private sector employment is strictly very competitive. 

Sir, this is because there is no fear of getting fired from job. There is no  performance measure in government departments. Nobody cares if the employee is fully performing or not per the job requirements. There is no accountability, there is no one to question. That's the reason most of the employees in government sector take things for granted as if they are the son-in-law of government.. My answer is based on government employees in Indian sub-continent (India, Pakistan, Bangladesh and Sri Lanka)..