My favorite example of a writer like this is Stallman. Whether I agree with or disagree with any of his particular essays, they are always immensely readable. His arguments are completely unobfuscated and easy to follow. His work is worth reading if just to see how complicated legal and technical ideas and arguments can be beautifully decomposed.
Now, this is certainly not the only way to be a great writer. Perhaps it is not even a way to be the greatest of writers. But it is very effective and, importantly, relatively subtle. It is so subtle, in fact, that I think many people do not recognize how much especial skill it takes and good it actually is.
This sort of skill is particularly important for something like the law which is inherently complex and tends to attract people very comfortable with such complexity. Exposing it simply is crucial. More relevantly for HN, this sort of skill is at least as useful for technical topics. It's certainly something everybody here should think about when writing.