Yeah, at the very least it is doing what it intended to do in that it makes people aware.
In my case, I knew about Cheapassgamer, but I hadn't been there in ages and my email was released to the wild long before I knew.
Probably more right than wrong!
HIBP
Like the Disqus one I mentioned above, it's not a site I use, but their software is "like" systems for stuff like Facebook, Wordpress sites etc..
In other words, it could be a third party that is accessing your data in conjunction with a site you frequent that get's breached and your none the wiser.
People feel incredibly secure on the net, but most would be blown away if they could see how much stuff is really going on. Just the old worms alone from years gone by, still scouring around hunting for ports that should have been long closed is mind-boggling.