OK I have lopped out a lot but wanted to comment on some:
Agree on Michael for sure. Billy was a game changer in the sense he was set up to be a bit of a hand grenade. Likeable enough but the points go to the producers for the stunt, not so much to him. Indeed, but you've got to think from a production POV - who was at the centre of some points of the series that changed their respective seasons? Billy is that. Dean is arguable, he was just a jerk IMO. Jerk? Yeah, probably. But he had his moments. Standing up to Rachel when she was a new housemate (and with no perception as to whether she would become loved or hated by Australia) was pretty ballsy. Plus he totally screwed up productions plans to try to boot him for violating their casting rule. David Hodis went in with the single schtick that he would shave off his beard (admittedly Ryan won his season with the single schtick of being a frozen chicken so... maybe?). And Ciera Eastin being on Game Changers was summarised as more than "She voted out her mom!!!"? David had more outside that. The way he exposed Lisa, outlasted those who were out to get him, etc. The Logans failed their task but producers manipulated it for them to go on and win, WTF? They FAILED. The point of bringing back the Logans is to harken back to another game-changer twist. But also to see if they could perhaps pass the task if given another shot. While there were suspicions about them, I feel like it was ultimately the window smash incident that was the final nail in the coffin. Bree was an accidental game changer Still a gamechanger. and the awful, awful Terri got lucky. Now I have beef with people attributing this to luck. Go back and watch the finale night - Terri's win wasn't luck, it was producer manipulation. Extending the voting deadline, continuously showing the percentages that had Ben/Rory winning and asking "IS THIS WHO YOU WANT AS YOUR WINNER????!?!". While we can knock AMav for his manipulation to try to get Michael / Ben -> Tim / Skye to win their respective seasons; at least it wasn't as ridiculously unfair as 2008 was.
Could your complete list be the worst cast ever assembled? It's a yes from me lol.