I'm not sure if this post was brought about by anything in particular or if it is just something she has been thinking about for a while, but either way Alyssa articulates some valid, if uncomfortable points.
While optimism and a positive attitude are generally good qualities to have, accountability is also very important. Inherent in this is recognizing and accepting failure. Although this process can be painful in the short term, finding the causes of the failure and correcting them it will ultimately lead to improved results in the long term, making future successes that much more rewarding.
As David Shenk, author of The Genius in All of Us put it, "...great work is, for the most part, painstaking and cannot happen without the most severe (and constructive) self-criticism."