We get notifications when someone "thanks" one of our posts, but nothing if they reply by quoting one of our posts.
Yes... I understand I can subscribe to a thread. But that's not the same thing. If you subscribe, you get an email notification every time someone posts in the thread... not just when they quote one of your posts. I don't know about the rest of you, but I certainly don't want my email blown up because I subscribe to a thread that winds up getting multiple posts.