Here the people excluded are non-residents and non-citizens. So the system works for all residents and citizens, to whom the government is beholden. It could just as easily be extended to include foreign workers, and they've been moving in that direction already. This is an explicit decision not an implicit one. It's not that the system wouldn't be able to support them due to some fundamental or intrinsic issue, it's a choice. That isn't true of the US model.