while i agree with the creator of the thread, i also can see how it is flat out impossible to expect anything less than flame wars
That basically says it all and it's 100% true. Not everyone, but a lot of people fall into this trap. Case and point. If a person describes a flaw in a game/company they don't like, they'll do it in a derogatory way. If it's in a game/company they do like or support, they'll downplay it as if it's just a simple big or flaw. It's human nature and there's rarely a way around it.
About the bottom line thing, i think Mossfan said it best
In a way, people are forced to buy a game they don't intend to at all. We're all here for a reason and it's not just because we like video games. There are tons of people out there who casucally like a game, yet dont feel the need to nitpick it, analyze it, and share opinions about it with other gamers. Most of us here are a lot more serious than just that. That's why we are here, so in that sense, a lot of us are going to fall into that boat of "Buying the game regardless because we need to either see it ourselves, or just own the newest game's rendition".
If we can kind of agree with what i said above about buying it regardless, and how many people fall into that trap of supporting one company over the other (in any way), then it's going to be pretty obvious the chaos a complaint thread will cause. Nevermind the flamewars that will come, but imagine how many arguments just would come in other threads like "why post that here, take it to the complaint thread" every someone just wants to post a simple comment. We should take a minute to realize the age spectrum here and maturity spectrum that goes along with that. That's a lot of ill will that could be generated for things people are going to post indirectly in various other threads regardless.
All in all, we have anyone from the ages of 12-42 posting here at any given moment, nevermind how everyone within that spectrum has vastly different levels of maturity. The mods have enough work as it is already. Adding a specific thread just for complaints would only go to concentrate a lot of time and energy to moderate one thread needlessly. There's just no way to hope that a thread like that would stay civil with the huge differences everyone has in age, opinions, and levels of maturity.