Absolutely. I think it's a fundamental fact of human psychology that we are attuned to subconsciously figure out the underlying rules behind a system and then plan and act based those rules, meaning that a system that does in fact follow fundamental rules is both predictable and a pleasure to use - that's probably partly why systemic games are so enjoyable. With the corollary that systems without an underlying and consistent ruleset are harder to understand, provide less venue for the user to produce innovative use cases, and seem to come (at least for me) with an unconscious sense of unease with using them. It's like UX but at a more fundamental level.