I did not reference your stuff about the positive uses of law because I was trying to construct a different argument. I'm a utilitarian, so for me, by definition, the society with the highest average standard of living is the best. I wanted to demonstrate that law raises the average standard of living, thus law a lack of law is inherently immoral.
It's like you didn't even read the part about the positive uses of law. Just because I think something is inherently wrong doesn't mean it doesn't have a good use.
Further, in smaller communities this isn't an issue. Nobody is going to be able to go around being a complete asshole in a lawless society because somebody else will make them regret it. Even if nobody else can, the community can do it. Even the vile, wicked murderers in the lawless old west would never ride into town and start killing people, at least not without a lot of help, because they'd have a lifespan of about ten minutes if they did and the risk clearly could never be worth whatever reward they could pull from it. (Unless they were trying to die, and law couldn't stop that. Actually, law might encourage it.)
But I think you're quite wrong that in small communities no one would be able to go around acting like a complete asshole. In a small group of people one is always going to be the most powerful, whether they get that power by being intimidating, ruthless, physically strong, persuasive, or what. Whether you are talking about the chief or the best hunter of some isolated tribe, or the owner of a feudal estate or slave plantation, history is full of people who got away with all kinds of horrifying things including murder, rape, enslavement, forcible castration, and torture. There are also many historical examples that people will cooperate to oppress others, defending each other against anyone who might want to stop them from doing so.
All that aside, from a more technical point of view it is just much easier to use a story to show that a specific type of government or law is bad than to try to show that all law is morally wrong even though it can have good effects. Any concept that abstract and non-straightforward is difficult to illustrate with a story. (By non-straightforward I mean that you can't just show all law causing bad effects, since you agree it can cause good ones.)