Welcome to the crowd if there is no one to employ you.

Start your own company, create your own product and raise the money to fund its operation. We are younger, 57, 60, 62+ young men who decided not to be employed but create a product to aid man-kind.

In many parts of the world, the retired professors still hold academic position and continued to involve in exemplary research. These individuals can still hold a lab, apply for funding, be a part of a program funding, and publish a lot and advance the field. I have worked with a professor in Chicago, when she was 80 years old (retired about 20 years ago, when I joined her lab). What it shows is the passion and dedication for a research career.

However, it might not be the case in may developing countries. Once they retire means, they are 'out of status' so to speak. They have nothing else to do! In such countries, industries hardly hire them as they are too old for their jobs.

We often see people who are enterprising type, join industries to make more money! People want a stable job, they join academia! In academia, in many cases, these individuals might not have not earned any reputation in the field, and no publication and what so ever! Because, there is no performance-related pay or promotion. Publication is not mandatory for salary increase or to get a promotion! They may not do any research or hold a patent. With out these qualifications, the industries might not be interested.

On the contrary, someone with long years of industry experience (e.g. R&D experience) can contribute well in imparting their practical knowledge. Some might want to work as a private consultant rather than returning to academia as the salary is usually poor (comparable to the industry pay).

Coming back to your question, your assertion might be wrong! Someone who have never contributed to their field during the tenure, might not contribute anything at all, if he/she was hired. In such scenario, it is better to hire a young and enthusiastic lad with a burning desire to do research.

Although we cannot generalize everything, and there are exceptions to the rule, this is pretty common scenario, in many parts of the world. I would be very happy, if these individuals really contribute in their respective field. For example, many with pharma/medical background move to pharma after their MD or PhD, because the package is good. They might be working in clinical areas and might not be anything to do with an R&D department. Many academicians will not leave academics because it gives them the freedom to do the research.

So, my argument will be that it will be case by case basis. Not all the retired people might be useful or contribute to the development of the field of their choice. They simply wants to return back, because they want to make money, not because they have the passion for research!

As pointed above, why don't they start a company, offer jobs to deserving individuals? Why don't they create more jobs? They don't want to start the company, because they don't want to risk their money.