The challenge is, how do you make the process of curating content easy (but not too easy so people make a mess of it), fun, and rewarding so that you keep doing it? I don't think Quora has come close to solving that problem yet, and it's not clear to me they are seeking to do so.
There has been a lot of comparison to Pinterest, where I am also an avid community member, as Pinterest's main concept is to curate visual content on the web to organized boards. They currently don't support pinning other types of content (links, text, videos, etc) unless you manage to take a screenshot of that text and pin it. Their business model seems to be allowing products to be part of this infinite interactive museum where people have freedom to curate their own arrangement of visual content around topics. Sometimes these visuals are photos of trees, but often they are images of products that one can buy. They don't force you to pin products, people do it naturally. Brilliant business model. Their UI has its challenges to, but at the least I understand why they have boards, and the process in which to curate content is front and center in the entire site's experience.
Meanwhile, Quora boards feel like a taked on afterthought. Here we have a clearly data-driven company that adds the least common denominator to test a feature out, to see if it catches on. The trouble comes when that feature, to be done well, requires a much more extensive look at what that feature means in the context of human interaction, why we want to curate content, and how this process might be enjoyable.
There lies a great opportunity here for those of us passionate about the Quora community to curate content at a level that would provide great value both for users, and for Quora as a company. The problem is the implementation, as well as it's current place in the entirety of Quora's user interface, isn't carefully thought out in order to reach this goal.