I really liked the phrase "diagonal shortcuts" from the OP. It brought to mind a physical metaphor for what's meant by software having only orthogonal functions

I really liked the phrase "diagonal shortcuts" from the OP. It brought to mind a physical metaphor for what's meant by software having only orthogonal functions: on a college campus they usually pave orthogonal sidewalks, and inevitably you find diagonal paths where students have cut through the grass and trampled it down to bare dirt. It's ugly in some sense, but it's what everyone wants.