The problem that we were having over time is that prior to release, OTs would just be havens for the hardcore superfans. So when the game comes out and people start playing, people that hadn't taken up residence in the OT for the past week making sure everyone had their tickets for the hype train would start playing it and commenting. Now, sometimes these impressions were positive and it fit right in with most of the population of the thread. But sometimes, these impressions were negative. And this is where the trouble started.
The thing that we want to convey is not "hype is bad and you should stop being excited about things." However, we have come to realize over time that hype culture can be very toxic to honest discourse about a game's quality. When the superfans have already set the tone of the thread such that this is a place to praise whatever game we're talking about as the greatest thing since sliced bread, the people who would stroll in to say "you know, I've got some complaints about this game" would tend to get shouted down in quick order.
So, the decision we reached is that we really needed to do something to try to combat this. OTs are not designated safe spaces where only those with good things to say need apply for entry.