I just don't see the point in responding to request threads you're not interested in. At all. If you feel insulted by the fact that the guy takes artists for granted, well, that's too bad. Just remember that your actions reflect on the forums as a whole.
I mean for the love of God, do you go around looking for job postings in the newspaper, and then call those jobs to tell them in an abbrassive and haughty tone why you think their job posting sucks and why you're not interested in working for them? Of course not, because it's completely ridiculous.
The lack of replies to their request thread is a strong enough message, and even THEN, just because no one's posted on the actual thread, doesn't mean the OP didn't get any PMs from interested parties.