Good point, Mark. There's actually a chapter in my Hibernate book that explores just that point, along with other optimizations around the SessionFactory, Session, and the Hibernate Core in general.
The example is purely for
andragogical purposes. Each method is contains all of the information needed to perform the database interaction, without calling any helper classes or singleton methods or anything like that.
When you're learning, I think it's good to see as much of the plumbing as possible. In production, it's another story.
-Cameron McKenzie