USDA Is Not an Agency

My title isn't quite true, but here's my point:  Megan McArdle writes about federal regulations here.  In doing so, she mentions the "Department of Agriculture" twice, both in contexts which are vaguely adverse.  The problem I have is that USDA is a bunch of different agencies, each with their own missions and regulations, each with their own attributes.  To write of it as if it were a unitary agency is simply to misunderstand and oversimplify.