Not only that, but that they can look very clearly at cost vs benefit. With a citizen, who is unlikely to move anywhere else, you can look at lifetime care costs and reduced earning ability (at least in the average case), and say outright that it is sensible to pay $100,000 to save many times that on a lifetime of ineffective care and reduced potential. You can also look at the public health impacts - treating one patient might reduce the risk of wider infection in society, which can also be placed in the cost-benefit analysis.
This is more difficult with American states (because people move between them much more- the payment comes from one state, but the benefit is spread out), and more difficult for insurers (because they are subject to much greater short term pressures, and can't look at wider benefits).
From the article:
“If it is cost-effective from a societal standpoint, it is not necessarily going to be cost-effective from a health plan standpoint,” said Dan Mendelson, chief executive of Avalere Health, a health care consulting company.