https://en.wikipedia.org/wiki/History_of_health_care_reform_...
Or if that wiki is wrong, feel free to correct it.
In other words, I don't think it's the age that's the problem. It's that most European countries don't mind as much having their national government run things while the US tends to push more federalistic/distributed systems.
In fact, I doubt most people in 1942 would have even thought about the federal government's ability to regulate healthcare. Wickard v. Filburn was decided in November, which is the case that really opened the interstate commerce clause. Heart of Atlanta Motel v. US wouldn't happen until 1964, only then finally allowing federal laws to prevent restaurants from discriminating racially. If the federal government can't even set standards for restaurants it's rather hard to argue they have the ability to regulate hospitals and healthcare that happens inside a state. Medicare wouldn't get founded until 1965, it's not a bit coincidence this happened after SC decisions widening the interstate commerce clause.
The powers of the federal government looked extremely different in 1942 than they do today.
Well, most of Europe' social welfare systems were wiped out by the end of 1945 and were then rebooted with forethought and precedent of what not to do. The US is an archaic hodgepodge of systems over a 100 years old and were created with no precedent to model from.
People defend this system because their lives and livelihood are tied to it. It is dumb, but without a thing like a world war to wipe the slate clean it is what we have to work with.