As has been hashed out before, force fetch is advanced obedience training using the Fetch command, not a means of forcing a dog to retrieve. Done correctly one will see an improvement in obedience across the spectrum in addition to retrieving. In this case, force fetch training is being used to correct an unwanted behavior during the retrieve which is an obedience issue. The term, like so many other dog training terms, is derived from horse training and breaking a horse to allowing itself to be ridden which is another topic all its own.
Like horse breaking force fetch has multiple methods of reaching the final goal. These methods can range in appearance from mild to harsh with many, supporters and detractors both, only seeing the seemingly harsh end. Many of the latter likely use methods of force fetching from the mild end not knowing they are doing so due to not fully understanding the concept.
