James Grimmelman has taken Lon Fuller's classic text, the Morality of Law, and used it to measure software, evaluating the degree to which laws embedded in code can be thought of as "moral" laws:
Software is unambiguously better at legality than law itself on three counts (prospectivity, consistency, and possibility). It's strictly inferior to law on two (publicity and comprehensibility). One (stablility) is a complete wash. The last two (generality and reality) depend on very much on the kind of software we're talking about and how it's used.
Overall, then, there is no simple answer as to whether software is better than law or not when it comes to the conditions that Fuller would say make any system of authority worthy of obedience. It respects those values more in some ways, less in others. Whether or not any given software system is a good replacement for a legal alternative will depend on which values of legality are more important to you (a large part of Law and Morality discussed the ways in which these values are necessarily in tension). Further, it will depend on how well the software system's designers handle the challenges of explaining accurately just what it is that their software does, and those explanations will be more or less persuasive for different kinds of software.