That doesn't seem wild at all. Laws are written by humans, and, as such, there's inherent ambiguity.

Given that, would you rather have a case tried in a court that has only tried a handful of other cases, or would you rather be in a court that has handled a mountain of cases, with lots of information as to what the law really means, as it has played out in real-life scenarios?

Being tried under a legal regime where there is a ton of past history seems a lot easier to reason about than one where there isn't much.

> It's as if one is joining a club that has rules of business conduct clearly documented.

Well, yes. The law is the law, sure, but the "documentation" is much more than just the law, as written.