If you start work on a new project, you often take old code and adapt it to your needs. That is a very sensible approach, because you work off a "proven" code base.
Jarkko's post that you shouldn't use this or that PostgreSQL tricks although they are allover the OpenACS code just "inspired" me to post. If we have commits with diffs, we would have something like code reviews and I am convinced that we would have much less hackish or outdated code in our CVS repository.