>a pretty dry read
I'm not sure what you mean, except you didn't enjoy his style? Gee, he seems the opposite of dry to me–a very warm, friendly, human voice. If you think he's pretty dry, who in the field do you prefer?
I don't think you can have read Zinsser. You misspell his name, and it's hard to believe your sentences are those of someone who's heard his message:
"Not to be an HN contrarian, but" – this adds nothing. The reader of On Writing Well learns to cut every unnecessary word.
"it's actually a pretty dry read and does not itself, in my opinion, reflect good writing" says unclearly in 16 words what could be said clearly in a few. Cut "actually", "in my opinion" and "itself". Does not reflect good writing – do you mean "it's not good writing"? i.e. "it's bad writing"? I'm not sure what saying a book "doesn't reflect good writing" means, but seemingly something other than its not being written well, or you would have said so, the reader assumes.
"unfortunately I wouldn't say Zinnser's book is a piece of writing I would admire." Again, the head spins, although what you're trying to say seems simple. If it's "I don't admire it", why not say so? If something else, say that. Simplicity! Etc.
I encourage you to give him another go!