Your statement is a non-sequitur. The Clojure community on the whole is extremely friendly -- that he takes a stab at Ruby does not invalidate this fact. One person blogging one statement does not a community make.
No but if this author thought this appropriate for the community's consumption, then it would make someone outside the community think that the community may be less than friendly.
Of course you are correct. Unfortunately I imagine that every programming community suffers from this.
Unfortunately, the blog post author is lots of peoples' first exposure to the Clojure community. Not a great first impression.
You're right. And I've seen several public requests in #clojure for him to stop with the unproductive language wars, but he ignores them.