Dear Dixit,
In my opinion, generally, any employee who has had a contented career and a planned life would always eagerly await the age of superannuation to turn a new leaf in his life. But, there can be exceptions. One might have started his career late and could not have still settled in life like unaccomplished commitments towards late born children such as education, employment or marriage etc.; some others might be obsessed with the routines of their own employment so that be ignorant of the alternatives for being within doors. Only such people will desire to be with the organization even after their retirement on superannuation and therefore it cannot be simply found fault with since the adage goes " Udhyogam Purusha Lakshanam".
Reemployment of an employee in the same organization after his retirement on attaining the age of superannuation can be done in two ways - one is giving extension of service at the discretion of the employer before actually allowing him to retire and the other is engaging his services as a consultant on a contract for service after his actual retirement.
Extension of service of an employee of workman cadre can be an example to incite other employees to put up such a demand and can be a case of favouritism.
Engagement as consultant on contract basis can be adopted in case of senior managerial cadre of professional and technical positions only. Such a step may be indicative of poor succession planning and may even lead to heart burn of the immediate juniors aspiring for promotion and result in higher attrition rate.
So the ultimate decision in this regard rests with the wisdom of the top management depending on their compassion as well as compulsion of their business needs.