One among our many typical human inclinations is to judge things on the basis of their external form. We know this and create maxims to try and counter this tendency ("Beauty is only skin deep." "Don't judge a book by its cover.") and these are worthy efforts. However, they also reveal how ingrained these tendencies are. Philosophical Daoism would, I think, question whether we should judge at all, but we need not open that can of worms in order to appreciate one of the reasons Zhuangzi chose as his exemplars of sagacity men that society would generally have spurned.
There is a sense in which Zhuangzi's entire project could be seen as an attempt to shatter the many self-limiting and self-imposed mechanisms by which our minds have learned to engage the world. Right and wrong, good and bad, beneficial and harmful, affirmable and unaffirmable, acceptable and unacceptable, beautiful and ugly — all these and many more determine our relationship with ourselves, others, events and the world generally. Deconstruction is his constant watchword.
Thus, Zhuangzi would perhaps first have us take a look at how we judge others. But there are other lessons here. How we judge ourselves is ever much as, if not more important. It seems likely, in fact, that most of our criticism of others is an outgrowth of our self-criticism. I am of the persuasion that the greatest part of my anger at injustices in the world, for example, are a projection of my anger toward myself and my fate. This does not mean there is no reason for anger, but only that there is "anger that is not anger" and then there is anger, and these are worlds apart.
Another question Zhuangzi might have us ask is what role the very infirmities of these men had in their having become sages. I am fond of quoting the obscure phrase, "every enslavement is also an ennobling". Those things that challenge us the most, including those which seem the most un-sagacious, are precisely the occasion for our growth. Not in overcoming them. That is the popular wisdom and the cliché. But in breaking the fetters of our attitude to them. In learning in what way they do not matter. In embracing ourselves and them fully. In realizing there never were any conditions we had to meet to be fully affirmed as expressions of Dao. In writing incomplete sentences and not giving a damn. The rest, the change, follows as a matter of course.
One of the convicts, we are told, viewed the chopping off of his foot and all the disgrace and failure that that was intended to covey as no more than a clump of soil falling to the earth. He had realized the view from Dao.
You can check out Scott's writings on Zhuangzi here.