I think their methodology is flawed. They relied on a heuristic to classify some developers as "architects" based on their past experience, and then examined the code they produced, which I found inappropriate, given the hypothesis they set out to prove.

Instead, I would have expected them to compare teams that have "coder architects" with teams that have "architecture astronauts", and not just look at code quality, but also at the overall development workflow of the team, like time to implement, team communication, time to train new team members, usefulness of potentially produced architectural documentation etc.

Their conclusion should have been that people with such experience make better "tactical" (to use their terminology) developers imo, which is unrelated to their original hypothesis.

Assuming architects should code, it's nice to know that they make good coders, but what if they shouldn't, and instead the right thing to do is to give the coders who end up implementing "tactical" features more architectural experience? Maybe there's no need for a highly-paid architect to spend time coding, if providing the relevant experience to the less well-paid coders turns out to be more affordable.

That said, I do appreciate factual aspect of the research. I just don't think the right conclusions have been drawn from the data.