That was probably a newbie that was fortunate to get owners that rate well. I saw that on the support forum and TBH it didn't garner much sympathy. I think a bad rating is below 4, and a bad average rating is below 4.3 for me. You still get a bonus, but less.
If owners do rate below a 3 or 3.5 either the writer is really bad (and some are), but some may rate just to get points for themselves and feel being anonymous protects them and hope the writer continues. To me, if a writer was that bad I would rather not have them there. I had one rating of 3.5 and messaged the owner to say sorry I was not a good fit, and that I would prefer not to write on the forum if they could confirm it I would unsubscribe. They refused to tell me who they were and proceeded to tell me how all Postloop owners wanted questions framed. I made threads with questions, but he didn't like how I framed them (too intellectual for him) and claimed he was an expert as he owned several forums.
He is now banned, and most of his sites have been closed down as he had no traffic (real or otherwise).