So? 50 get accepted out of every 2,000+. They admit their prototype wasn't well-polished.
This is like the relative of a famous celebrity (or scientist) not getting into an elite school and admitting some part of their application - essay, scores, whatever - wasn't as well as it should have been.
Am I the only one insulted by this article? If anything, it's also irresponsible of SF Chronicle of sticking both of these girls in the limelight. Imagine if she wasn't Zuck's sister; should your rejection somewhere be published in a major newspaper?