I think the issue with the commentaries happen with alot of older stars of older shows, I think doing a Commentary is so foriegn to alot of these stars. They just don't know how to approach such a thing. As was noted alot of these stars don't even see much beyond the dailies, i.e. they don'y look at the finished product. So when they sit down to watch a 40 year old show, which they've probably not even seen in its finished form it does ofter become them just pointing out people and places.