Why NOT formalize rules to some extent? Having a hidden set of implicit mores is far worse. In fact, you can easily read this post as a pro-COC argument.
After all, the author is able to make a really strong case that he didn't really infringe on any part of the COC, and that the COC was poorly constructed to begin with. With no COC, he'd have to just be saying "I think Numfocus exercised bad judgement," which is a much harder argument to make since it's so subjective.
We're professionals. Rules shouldn't be implicit in professional environments. Explicit rules are easier to use, and they make it easier to hold the authorities accountable for misusing them.