In the past people often worked in their businesses until they died or were no longer able to continue, whereas today most industries have set a definite retirement age for their employees. I personally disagree that replacing elderly staff with young recruits would be unwise.
First and foremost, a large majority of workers lose their strength as the become older. This is mainly because the human body has limits and working for a long time, say, 30 or 35 years, can affect it negatively. For example, young industrial workers tend to work for five or six hours before they take breaks while older ones usually need to rest every one or two hours. This means that productivity levels would certainly decline.
Furthermore, new employment opportunities for young people are very limited. Most companies not offer more than a few jobs every year and try not to increase their staff members dramatically to keep expenses low. Consequenly, they should definitely lay off some of the older personnel to make room for youths, especially those around 20 to 30 years old who are about to form families and support them.
Finally, although some people might argue that the experience and skills of old workers would be lost when they retire, they should remember that this experience is mostly with old or outdated equipment and technologies. As a result, it is less likely that their employers will need their abilities in the long run and younger workers can be trained to work with modern machine such as computers and lasers.
In conclusion, i believe companies need to force their elderly workforce to retire and employ younger workers to replace them.