While there's merit to what you say, I am thinking of it more from a "re-finding" it perspective. Maybe it depends on how a person's "skull hard drive" stores info. I'm just thinking about a guy who's seen something, a few months later is in a situation where he suddenly thinks "hey, I saw something that might work here", and wants to retrieve it. Since the search engine here is pretty specific, if you don't have exactly the right terminology that the original author used, you'll likely never find it. At least with a unique forum you'll have fewer posts to sift through.