Good work very much doesn't speak for itself, typically software problems represent management problems more than a lack of people trying to do good work. This is such a wild claim vs what I've seen that it makes me quite suspicious of this article and the one before it. It is a nice story that there is a high-productivity engineer who just does great work and everything steams to a happy end out because they are just that hyper-competent. But that is a myth, and probably more a tell that the narrator is misreading something about the situation.
This looks a lot like a manager-once-removed undermining a reporting manager by supporting an engineer to go rogue. I'd believe that the engineer is actually doing good work, but then that suggests there are problems in the management culture here. Either the blog writer doesn't know how to manage managers, or the middle manager has a competence problem. From that assumption I'm not totally surprised that there are problems in the resulting software that one unusually capable engineer can expose with a few weeks of rogue work.