First you cannot retire when you are 50, only when you are 65 (Portugal), so if you resign you don’t eat.

Second, the fact is a 50 year old person knows a lot more about the job and has more qualifications than a young one, the young one cannot do the job as well as the 50 year old. 

Although I can see what the author altruistically advocates for young people, the facts is we only have this situation because we have 

an economical crisis and a lack of talented work and skilled labor as never before seen. It is true that it is better to have a decade of inactivity at the end of life, but it is also true that at the beginning 

you can stay with your parents and not suffer because you don’t know how you are going to pay for your house and food, whereas if you do that when you are 50 you are lost.

http://www.bbc.co.uk/news/magazine-17855240