Sure, for a skeezy site. The parent was talking specifically about php.org, I can't imagine any real risk for a site like that exposing their visitor ip log.
It's not just that. You can get an idea of the traffic to the site if you watch for a while. When that information might be commercially sensitive then it could be a genuine issue.
For example, nba.com has been averaging about 3 connections and 1021 idle workers while I've been watching it. That's perhaps less traffic than you might expect? I don't know, but if I were paying for ad space I might be interested.
AOL deidentifed search data still allowed some people to be identified. When name is tied to some medical condition related search terms, it gets embarrassing...
Yes, it's potentially an issue.