Later I registered and saw that it's a really good website with quality content, but my first impression was not very good, precisely because of the obnoxious login wall.
People are going to register only if they want to interact with the website.
If I just want to read content,I shouldnt have to register.Stackoverflow made the right call and today it's infinitetly more popular than Quora will ever be.
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.