It's all about projecting a certain image and to use the word place or placement gives the idea that some thought and care was put into rather than it being a random haphazard occurrence such as "left" or "dropped off", "deposited" or handed out.
When you give away a litter of puppies, it sounds better if you say they were "placed " in new homes or "placed" with a new family, even if they were just gotten rid of to whomever would take them.
As far as the term "Publisher", again this is about projecting a more elevated image. A paperboy or paper carrier, delivers, drops off or distributes newspapers yet he is not considered to be a publisher. The Newspaper Publisher is a usually the owner of the Paper such as a large corporation. JW's used to use the magazines as an avenue to speak to people about their message and since they were part of a printing organization, the probably went with a newspaper term that projected a certain importance to what they were doing..
Now that they're silently standing by carts full of literature, I'm not sure what they'd call this. Possibly Cart Attendants?