Harsh. Too harsh. I’m a Perl programmer, and I use LWP::UserAgent all the time. I tend not to touch the $ua->agent, or I append contact info or a URL to it, so people know what I’m doing.
In particular, I wrote a Jabber bot that periodically goes out and fetches RSS feeds (via LWP::UserAgent), then retransmits those feeds over Jabber to its subscribers.
Seems to me you’re curing the symptoms — it’ll probably cure the disease, but you might kill a few patients along the way.
@Platinax: The WordPress user agent is actually used for trackbacks and whatnot, IIRC.