Some bloggers associated with the American Civil War, such as J. David Petruzzi and Brooks Simpson, have recently posted about some division between professional and amateur historians.
I have actually spent most of my working life not with academically respectable publishers, but those who produce "coffee table" books. When I worked at another place, I found myself beside a PhD candidate who had the worst possible opinion of any writer who signed a contract for a "coffee table" book (although he was happy to do them himself, under a different name). Far from wanting to appease this snob, he only made me more determined to bring the good qualities of book editing I learned with the mass market publisher into his snooty world. It's not easy producing a book for the Masses.
I'd go so far as to say that if one wants to spend time debating amateur versus professional, it's not just the historian's craft that needs to be categorized, but also the writer's. It's easily possible for a professional historian to be an amateur writer, the sort of person better off writing for the plaudits of their peers and not for real readers.
Hat tip to Civil War Memory.