It's just unfortunate he's distracting from discussing the content of the post to make a pedantic point that recurs on HN ad nauseam despite fostering no interesting discussion.
It happens. As you said, it happens recurringly. Generalizations can be an issue for a lot of people in a variety of topics, and his comment outlines his hope/a reason against people continuing the trend of generalizing engineers. Even if it is just the title. There's nothing wrong with more specificity.
He even apologizes for going slightly meta and off-topic. If anything, complaining about this point distracts from post content and fosters even less interesting discussion.