Comment by Panzer04

Because from a moral standpoint most people agree that we shouldn't allow people to go without treatment, regardless of their poor choices. From a national standpoint it also doesn't make sense to allow people to become cripples for lack of money, reducing their economic value.

Injuries also hurt, so it's not like people don't have other disincentives to avoid injury aside from the price. This isn't the case in other areas, where it's purely a monetary penalty and thus removing that penalty results in way more of that thing taking place.