High quality code isn't just code that performs well when executed, but also is readable, understandable and maintainable. You can't judge code quality by looking at the compiled result, just because it works well.
> One could also say that quality is related to the functional output.
Right, I said nothing that contradicts that ("High quality code isn't just code that performs well when executed, but also ..."). High quality functional output is a necessary requirement, but it isn't sufficient to determine if code is high quality.
It's not really subjective if you're at all reasonable about it.
Imagine writing a very good program, running it through an obfuscator, and throwing away the original code. Is the obfuscated code "high quality code" now, because the output of the compilation still works as before?
