No, he's right to complain. We really do need a tagging system so we can filter out the kinds of prediction statements we don't want to see. For instance, I resolved not to read anymore HPMoR (I stopped at about chapter 65) until I complete certain others goals (of which, I use PredictionBook to help with motivation), but it is very difficult for me to avoid spoilers with the site's current setup. I'm sure others have similar problems.
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.