Xunzi, a third century (BCE) Confucian philosopher, spent considerable effort denouncing the philosophies of others, including Zhuangzi. "Zhuang Zhou", he wrote, "was blinded by nature and was insensible to people." (Xunzi 79/21/22; Knoblock)
His point, I believe, was that Zhuangzi took nature as the whole and humanity as a part of that whole; he read humanity through the eye of nature rather than nature through the eye of humanity. For Xunzi, nature, read through the apparently inherent moral sense of humanity (though he thought humanity immoral), was essentially moral. For Zhuangzi, humanity, read through the apparent amorality of nature, was essentially amoral.
Xunzi was worried about morality, but from the Daoist perspective, his morality was the cause of immorality, while Zhuangzi's amorality resulted in true morality. The imposition of law from without, whether it be celestial or the whim of a dictator, only serves to bring about lawlessness. (This is also the foundation for the Pauline doctrine of grace: The law causes one to transgress; grace allows one to be forgiven; living in grace, law is no longer required, its end having been achieved in the negative by having demonstrated the need for grace, and in the positive by having allowed grace to write the law on the heart — “Love God, and do as you please.")
This brings us back to that persistent problem of the relationship between "Heaven" and humanity. Both Zhuangzi and Xunzi agree that there is a possible disjunction between the two — humanity is capable of acting outside of nature. For Xunzi, humanity acts outside of nature when it fails to act morally. For Zhuangzi, humanity acts outside of nature when, in the application of morality, it fails to act spontaneously. But is there really a disjunction, a problem?
I think there is. Though it is impossible that anything could be outside nature (Dao), and thus all that humanity does cannot be other than what nature does, still humanity is capable of self- and nature-destruction. (Though nature, as emergent Dao, remains ever-emerging.) Call it free-will or call it a quantum of Chaos, or just accept it as unfathomable paradox. Not-One is also One.
What all this resolves to is an affirmation of a belief in the normative; there is a place for us to speak of a "better" way to live. Zhuangzi, for all his aversion to value judgments, points to what he believes to be alternative ways to live, and suggests some are "better" than others. But that which makes them "better" is not based on any moral judgment or a closer approximation to "truth", but simply that they make for a happier life. And this, I think, is the most powerful apologetic possible. Make your choices, remembering that they have no bearing on anything beyond that.
You can check out Scott's writings on Zhuangzi here.