I don't think the low-quality general answers from some of the high volume contributors really matter; I'm a lot more into the niche experts, and Quora makes it easy to find those people. (Marc Bodnick upvotes are so common as to be essentially content free, although his answers are great; there are a lot of users who contribute lots of crap with no actual knowledge, across a range of categories, and a number of users who are only contributing in very well defined areas of expertise. e.g. Gus Fuldner's PCI related answers are great, and there are a lot of domain experts and people with first-hand knowledge who post on Quora.
If you have a problem with Quora, follow better users and better topics.
The boards product is IMO pretty ill advised. Quora is doing it because they want to be a repository, easily searched, of a lot of interesting information, but they didn't take into account the second order effects of attracting a lot of boards users to Quora.
The funny thing for me is that the OP joined Quora (I think) during the big wave of idiots in December 2010. ("Scoblegate"). People said all the same things about death of Quora then, and in June 2010 when it opened up to the public. I suspect the average IQ of Quora users has been in strict decline ever since the first user was added after Charlie and Adam.