Black Locust is often the only species approved in lieu of pressure treated, and white oak is generally not placed in that category. Don't ask the reasons, that is just the way it is. Black Locust is the only non-treated wood approved here for direct contact with concrete. Personally, I tend to put 2X PT underneath any wood in order to satisfy the code. Often times the PT is anchored to the foundations as per code, even though the Plates will just sit on top of it. Silly, but it makes the inspector happy so that's how we do it.

We always say the only purpose for anchor bolts is that if a Tornado comes through, at least you will still have plates attached to the foundation...


As for the comment about the Amish,
Let me just say, a lot of times there are a great deal of specifics to the standards that have developped over the last 3 centuries, in reaction to the changing world around them. What you have to realize is that there has to be a line somewhere, and unless you understand in detail how that line was drawn it is going to seem arbitrary.