This isn't a complaint, it's feedback.
Specifically, for instance, what's happening when I view the "Happenstance" or "Recent predictions" lists is that I have to scroll, sometimes over a screen's worth, to get past a big chunk of predictions which I can tell are of no interest to me. This is demotivating (even though I have read HPMoR), a trivial inconvenience.
To me (and I can perfectly understand not everyone feels that way) the HPMoR predictions are noise, as are the private predictions such as "I will complete 100 push-ups by next month". I have no interest in refining my map of a fictional universe, or my map of a total stranger's motivational structure or muscular strength.
The appeal to me of PredictionBook isn't as a repository of predictions which are private to one person or that have a very narrow appeal. I can totally understand if someone else chooses to use it that way - though it's worth noting that its UI is not consistent with that usage.
What I'm expecting from PredictionBook is a diverse stream of somewhat challenging predictions which motivate me to take the risk of being wrong. What other PredictionBook users get in return is my occasionally contributing a prediction that makes the site more interesting, if by some epsilon value, for everyone else.
I'm not paying anything, so I don't have a right to complain about the service - I'm also free to quietly stop using it. I just thought it would be of some value to other users to give, as it were, an exit interview.
I'm not paying anything, so I don't have a right to complain about the service
Nonsense. You have a right to complain about anything. And some optimal prices are negative; there's nothing magical about a service you pay $0 to use (not counting the time you spend using it!) as compared to $0.01 or -$0.01.
The recent spate of updates has reminded me that while each chapter is enjoyable, the approaching end of MoR, as awesome as it no doubt will be, also means the end of our ability to learn from predicting the truth of the MoR-verse and its future.
With that in mind, I have compiled a page of predictions on sundry topics, much like my other page on predictions for Neon Genesis Evangelion; I encourage people to suggest plausible predictions that I've omitted, register their probabilities on PredictionBook.com, and come up with their own predictions. Then we can all look back when MoR finishes and reflect on what we (or Eliezer) did poorly or well.
The page is currently up to >182 predictions.