That assumes they're being objective; so far, it looks like jealousy or other frustrations manifesting themselves.
It'll be interesting to see whether or not they do like anything in future.
"To get a good review from uncov, you really have to earn it."
K said something relevant a while back: http://www.roadtoforbes.com/index.php/ksblog/why-the-80-20-rule-doesnt-always-work/
Anyway, even if they ARE utterly impossible to please, they're still telling you outright what you can improve. And an extreme view can sometimes help to put everything else in perspective.