I think you maybe over interpreted what they said, at least compared to how I interpreted or think about these things. Highly optimized or robust code or code

I think you maybe over interpreted what they said, at least compared to how I interpreted or think about these things. Highly optimized or robust code or code with a lot of edge cases is "messy" in the sense that there's a lot of details separate from the high-level concept that get mixed in and can't always be modularized or abstracted away or made simple. That's fine though if pieces of code like that are localized to the complex problem they solve. Simple is a relative concept that can change substantially. Simple code closer to hardware is messier that simple code at a higher level. I once interacted with a developer that optimized everything. Looking at the code, it was impossible to know what actually needed to be optimized because everything was optimized or had the appearance of so.