Putting effort into being obscure is often misplaced and adds a recurring cost in cognitive overhead. Furthermore, it creates a false sense of security when people think that something is unlikely to be exploited simply because an attacker doesn't know how to exploit it. So I agree with your sentiment in many ways.

However, I read your comment to imply that the author lost credibility with their take on security through obscurity. This seems like the exact kind of harmful binary thinking the article addresses. The author presents a more nuanced take on a mantra, and for daring to do so, you dismiss them.