Anyone that's worked with engineers can tell you that there are simply some people getting more done than others, in the same amount of time. Are there people producing bad code? Yes. But I don't think output is inversely correlated with code quality. In fact the people I've worked with that have the most output, also had some of the highest quality code. I've never experienced this mythological 10x rockstar figure that works alone creating impossible to maintain systems, and I've worked closely with dozens of engineers. He probably exists somewhere, but not with the sort of prevalence that justifies every programming productivity article ripping on his archetype.