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.