Not really. But we are - at least partially - convinced that it is easier to try to tell people what we expect from them beforehand, instead of doing that afterwards. Cleaning up after people who think that guidelines are not made for them unfortunately is a terrible lot of work. And since we all are volunteers, we try to reduce the number of such reworks we do.
Of course we don't think that our way is the only one the problem "internet directory" could be solved. Maybe it's not the best one. Maybe it turns out that is not even is a good one. But until now, there is no real example of how it could be done better, so the best thing is to continue in the same direction until there os proof that a dfferent direction leads to better results.
We don't have current figures on DMOZ, but in September 2006 (which is the newest data DMOZ published) we had a netto growth of 22k listings. Which includes removed listings. I don't have a precise number on these (because listings are removed by hand and by tools each and every day), but from the graphics you can easily see that at least 30k sites have been removed by an automated process in one go. Which gives a very rough estimate of about 2000 new listings per day.
Why am I telling you this? I don't want to say JoeAnt is bad. No, every directory started small, so does JoeAnt. Maybe it turns out that their concept is better than our concept, I can't predict that. But what I know is, that some things just don't scale. If you have 50 people, things just work different to having 500 people. And even more different to 5000 people.