Zinsser claims "The only important distinction is between good writing and bad writing" (page 99). What are the qualities of GOOD writing?
Good writing comes from a good heart, or one that is trying to be good. Good writing cares about grammar, punctuation, proofreading and appearances as much as it cares about content and organization. I must be too set upon these ideas, for I can't say much else about "good writing" at present.
For the sake of 125 words though, I must write. The idea of "good" is curious when one considers the surprising use of "good" in the Bible: "Why callest thou me good? there is none good but one, that is, God." By this standard, goodness is much more than we suppose, making "excellent" an exaggeration. So maybe good writing is God writing--and I think of God as a creator, a sustainer, the compassionate and merciful. Good writing would be all of these things.