I have not been on HubPages long, but, to me, this seems like improper etiquette. The appropriate response, in my eyes, would be to offer feedback and to provide editorial suggestions.
That being said, the world of journalism and writing can be highly competitive and cutthroat. I definitely understand the value of healthy competition. It sets the standard for all articles on HubPages to be of higher caliber.
They might suggest that an author take a cue from their own hub, without directly posting the url. Asking the author search it out, puts the impetus is on him/her to take an active role in self-improvement.
Like I said, I am new and unaware of the etiquette here. This, however, seems like the most democratic option to me.