I initially only saw your reply to tetrasodium, and assumed you were replying to all three of us in the same paragraph. I don't know if it was there all along and I just didn't notice, if you edited it in at some point, or if there was a problem with my browser. Sorry.
Now that I've actually seen what you were saying to me:
The less moving parts there are in the rules, and the more clearly defined what the functions of each of those parts are and how they relate to each other; the easier it is to change the rules or add new subsystems to the rules to suit your preferences without worrying about accidentally affecting other parts of the game in ways that you did not intend.
I'm thinking of the OSR ethos of "rulings not rules", and thinking of how a lot of OSR games that aren't just straight-up B/X clones tend towards very streamlined rules design. Thinking of The Black Hack, Knave, Into the Odd, Mork Borg, and Whitehack like I already mentioned. Tiny Dungeon and Quest are also coming to mind, but I don't think those are OSR.
Point being, if you want to encourage a culture of hacking and modifying the rules and thus not seeing the RAW and RAI as sacrosanct, having simpler and lighter rules in general would help with that; conversely, having a lot of complex rules would detract from that design goal.