Well in one sense this research is government subsidized, because it's paid for through tuition that is paid for through government-backed student loans. On the other hand, the government recoups that money so the actual subsidy is much smaller than the $575 million figure.
That being said, I think there is one very salient aspect to the whole law review system, which is that it engenders participation by a much broader cross-section of lawyers than is the case in other academic fields. Law reviews publish students and practitioners in addition to professors. You see articles not just about abstract theory, but the mechanics of some new tax provision. Even at big law firms some partners take the time to publish, not just articles but books. This is far better than say CS academia, where most articles are math-wankery that everyone ignores.
That being said, I think there is one very salient aspect to the whole law review system, which is that it engenders participation by a much broader cross-section of lawyers than is the case in other academic fields. Law reviews publish students and practitioners in addition to professors. You see articles not just about abstract theory, but the mechanics of some new tax provision. Even at big law firms some partners take the time to publish, not just articles but books. This is far better than say CS academia, where most articles are math-wankery that everyone ignores.