It is solid only if it were true. Alas it is not. The young will be getting into the business of subsidizing the old, above and beyond medicare. They are being asked to overpay for their insurance. The moral hazard was the nose in the tent, to move them from free riders into subsidizers - from one end of the field to the other. And we still have a dysfunctional delivery system, with not much competition and price policing to boot.
The base of any sort of social policy is the strong subsidizing the weak. The wealthy subsidize the poor, the old subsidize the young (whether they be adolescents, children or young adults), those who drive cars subsidize those who ride public transit and civilians subsidize the military. It's called living in a society. Your canard is growing really old and I advise you to find a new excuse to oppose this policy.