The summary: rules are devices for understanding. At least in artistic pursuits.
There are tons of rules out there for taking “good” pictures. And they make sense, especially for those who are just starting out or are only interested in getting decent vacation and family snapshots. They are invaluable for professional photographers who want to sell work to clients who expect not to notice they are looking at a photograph. But most of all, rules are there to help photographers understand what exactly it is they are trying to accomplish.
I’m working on an article to expand this idea, so check CommunityMX.com in the next week or so if you are interested.