I think Quora really wanted to be a private Q&A site, which imo is a legitimate choice in the space of possible communities. But then their results wouldn't get indexed on Google, and my guess is they decided that they needed organic search to get enough traffic to hit their revenue targets. So they have this grudgingly-sort-of-open results page so it gets indexed.

They don't have revenue targets. Quora is a zero revenue operation, they don't have a business model.

Quora just raised money at a billion dollar valuation basically. By comparison, Answers.com, a much larger site by traffic (with a $7+ cpm rate), was purchased for a mere $127 million, and was struggling to punch above $20 million in annual revenue.

Then you have to ask: what about Quora being worth $3+ billion, so their investors can get a return? There's no scenario that will ever get them there in the Q&A space (it'd require ~$300 million in revenue, literally impossible for them to pull off as is). They have to pivot out of Q&A because they can never justify their valuation, and they know it. To be worth that much they need to be a top 50 site in terms of traffic, and they're nowhere near that.

Wikia for example is substantially larger than Quora, and they couldn't even get close to justifying a multi-billion dollar valuation via advertising. Or consider Angie's List, worth $700 million, but tracking toward $300 million in revenue. Quora's investors have a huge problem ahead of them.

The other thing is they have Facebook's DNA where they constantly push the norms of user's expectations in the direction that they want. It feels slimy to geeks, but in a lot of ways it's the biggest story of the last decade of the web's evolution.