I've never used Kvetch, but can see the benefits of it; just your comment that some of the approved comments are now over matters integrated into the core makes it a useable asset. I cannot imagine, though, that there were really tens of thousands of comments which didn't make it through simply because they were spam, or gibberish, or whatever. Was someone there approving the comments all the time? Didn't the comments get run through Akismet to remove the trash? Even anonymous comments have their benefits; it prevents people from having to invent a fake name, for one thing!