I know from experience the difficulties an unusual name can bring, but Quora hasn't called me out just yet. I value their desire to build an authentic community, but other sites have grown without resorting to this sort of tactic. Fakes eventually are known based on their posts.
Speaking of fakes, Flickr cofounder Caterina Fake has had all kinds of problems due to her (real) last name:
http://caterina.net/archive/001011.html At worst, I've been asked if I was "one of them foreigners" by a landlord years back.
I remember one of the first bugs I ever fixed in a production system involved a Mr. Null who wasn't getting billed because he didn't show up in queries. I also once encountered someone named Mr. Blank though I didn't manage to ask him whether he had similar problems.
I'm not sure what you mean by an "authentic community". I have many friends on social networks whom I've never met in real life and whose names I have no knowledge of, but they are real people, and the relationship is authentic, based on our interactions.
They are not fake, they are simply anonymous.
Further, by having some anonymity, I can say things that I otherwise would not be comfortable saying. This is important on a site where the purpose is to answer questions.
Is it better to get a vague question or to have an answer that fails to reveal critical information because this information might make a business associate look bad? Or would it be better to be able to say X attempted to do Y because they believed Z, and I thought Z true, but Z turned out to be W and so Y caused a Q. X is a good entity, they just made a mistake here, so beware of this kind of error if you do business with X.
I would say that they're not "anonymous" so much as "pseudonymous", if you can even say that. A name is whatever a person calls himself; if it's adopted at the age of 23 and only used online that doesn't make it any less a name.
I try to say "legal name" rather than "real name" when interacting with people. While this is not perfectly correct (according to Wikipedia, in common law a "true name" is any name used non-fraudulently), it does help to remind people that assumed names aren't less real than given names.
For now. It would be a mistake to assume their system is so secure now (and forever into the future) that the data can't be found, or simply leaked inadvertently by Quora.
Speaking of fakes, Flickr cofounder Caterina Fake has had all kinds of problems due to her (real) last name: http://caterina.net/archive/001011.html At worst, I've been asked if I was "one of them foreigners" by a landlord years back.