The IP situation in the law is, how do I put it, screwed up. The U.S. taxpayer finances the creation of the case law, but there is no unfettered free public access to comprehensive indexed databases of decisional law (the access to US COA decisions being a much-appreciated first step).
As for commentary on the law, law review writers (some of them salaried professors of public or nfp institutions) are not paid, but that doesn’t mean (1) that their works are freely accessible; and (2) that somebody doesn’t profit from their writing.