Good article! I myself advocate the same whenever possible, but instead of axiomatic, I call it "building software in a coherent way", essence being mostly the same (theory is coherent when derived from a set good axioms). This article mostly concerned with entities, but similar things are true for relationships between entities. KISS is just a first approximation though. KISS might need to be applied at the meta-level as well to earn even more benefits.

In my observation most of the complexity in software is due to integrations with different domain models. I think DDD (domain-driven design) has good tools to handle those.