There's a related dynamic that I don't see discussed enough: simplicity is also harder to defend in design reviews because it looks like you didn't consider the edge cases. When someone proposes a three-table schema, the immediate question is "but what about X?" and the simple answer — "we handle X when X actually happens" — sounds like hand-waving compared to someone showing an elaborate diagram that accounts for every hypothetical scenario.
The irony is that the elaborate design usually handles those hypotheticals incorrectly anyway, because you can't predict real requirements from imagination. The simple version gets modified when real feedback arrives, and the modifications are cheaper because there's less architecture to work around.
The irony is that the elaborate design usually handles those hypotheticals incorrectly anyway, because you can't predict real requirements from imagination. The simple version gets modified when real feedback arrives, and the modifications are cheaper because there's less architecture to work around.