Interest to have some younger pilots is to maintain some transmission of knowledge. Younger people are there to learn to be able to replace the older one when the latter retire with their experience.
Degradation of formation and of morality is a big issue with youth. We often see 20 years old boys and girls ignoring definition of pressure, or logarithm and having unsafe life claiming they want to get pilots and chosing to buy fake licenses if possible and accepting fraud to get and keep the job. It is not only in India or Vietnam. Older people know it is dangerous, want to stay alive for their family and have a greater sense of responsibility. They know they are not God, and they will still do failures as everybody. Young people think they will never do mistakes and were living less meteorologic extreme conditions.
"And it is better to be an old pilot (who was able to survive) than a good pilot (having overconfidence in himself)"