I'm not a lawyer, but AFAIK, age doesn't influence your social score, tenure does. If I'm a 30 year old with 10 years in the company, I will have a better score than 50-year-old you who got hired 7 months ago.

The idea is that working at a company "squeezes juice out of you", so you should not be so easily fired after a long tenure, because the company got all the rewards from your juice, but you don't have much left. You can agree or disagree, but I have to admit that there is a logic.