While i agree with the thrust of the post, the argument is severely undercut at the point where the author writes that Quora's problem is that it doesn't solve a problem, and then immediately turns to observation that twitter doesn't solve a problem either, and is wildly successful.
True, that was not very well written. I meant to say that not solving a well-defined problem is not always a death sentence (see: Twitter, Reddit, etc.), but that it's still not a very encouraging sign.
I automatically discounted your entire argument based on those six words. If you're still unable to see the problem that Twitter solved, then you shouldn't be writing about tech, media or related.
To date, it's the most reliable, worldwide accesible, short-messaging, real-time propagation system that we've developed. Hands down, it has no competition. Not radio, not TV, not satellite communication and certainly not through any corporate-owned mouthpiece. It discounts trends, rumors, celebrity-induced Mass Sociogenic Illness or cheap propaganda.
It solved the problem of truthful dissemination through independent social verification.
If you did no not know that there was a problem with the truth as it was delivered to us prior to 2009 (which is when Twitter got its wheels) then you are one ignorant summbitch. Downvote for stupidity.
This is not cogent writing :P