Part of the problem is that you're right, identifying the value it provides isn't a quick process, and it's less because of design problems and more because the kind of value it provides needs longer periods of evaluation to identify.
It can take more than a casual visit or two to run across the illuminating post or comment that's basically a small dissertation where someone drops the knowledge.
And it will probably take a little bit before someone offers to just send you some hardware they're not using, just because you expressed an interest in something like it.
Some examples that might be more amenable to evaluation:
* This went viral in January:
"Holy cow! 14 minutes to solve the back of the card that has been bugging my family for 20 years! That is amazing!"
http://ask.metafilter.com/255675/Decoding-cancer-addled-ramb... http://mashable.com/2014/01/21/internet-grandma-mystery/
* This is completely non-viral a system administration question I asked a few years ago in a couple of different forums:
http://ask.metafilter.com/143963/Trouble-setting-up-printing...
Within a half hour on AskMeFi, someone picked out the answer to my problem.
It's probably notable that if you search for the exact title to my question (but not in quotes), you will get the SuperUser/StackExchange answer first in Google results (AskMe second). I did post the answer a Metafilter user helped me pull together on SU, so it's got the same content, but that's not where I got help.
The point is, it has an incredibly high signal-to-noise ratio and it's a damned shame it's getting penalized for it.
I think you'll find this to be a facet of every forum or comment box ever made available on the internet :).
>Seems like just another 'intellectual' echo chamber to me.
Are big words bad? What's 'intellectual' about it?
Thus something like a dated design might have an impact on search ranking.
I'm sure that over time I could grow to love MetaFilter, and possibly even find value in the qualities that give me this impression. But perhaps Google has an algorithm that lowers the rankings of sites that scare away casual users who stumble upon it from a Google search result (High and/or quick bounce rate maybe?).