I posted a one-star review in which I complained about the plugin's aggressive bait-and-switch, said I had deleted the plugin and installed WP User Avatars. Then I got this in my email:

"Jan Dembowski wrote:

I have removed your review.

If you want to leave a review then do so. But keep it about that plugin and do not use the review to make recommendations for something else. That is not appropriate."

This came from a noreply address, so I had no way to question it. My review did include a link to WP User Avatars on the repository, so if the moderator had said that was against the rules I'd be guilty as charged. But that's not what the mod said, and I think the mod took a subjective and rather expansive view of what a "recommendation" is. Not only did I not praise or recommend WP User Avatars, I noted that it was a pain to have to regenerate all my user profiles.

So it's quite possibly this plugin would have a lower rating if mods had not been summarily deleting reviews like mine. The bottom line is that when someone starts to make reviews disappear for murky reasons, they're wading into Yelp territory - they're giving users reasons to doubt the integrity of their review system and doubt whether it's worth taking the time to post honest feedback.