So a person in their 30s with perhaps another 35 years of ability to earn money should be protected from future pension loss by reducing the pension income of a 75 year old retiree?
Very fair.
Yes, why should the old one take the youngster's pension? Both should get an equal percentage of the pot, based on what they've put in, as opposed to the current situation where you may have a 61 year-old, who gets full pension and a 59 year-old who gets nothing, even though the younger one may possibly have paid more into the scheme.