The powers that be have decided that students will learn much better if the chairs in a room are arranged in a horse shoe rather than traditional rows. I'm a semi- traditionalist. I like my students to be able to see the blackboard. I like to be able to walk around the room and see what they are doing, as they are doing it. I like it when there is a little bit of space between them so that if someone had onions for lunch, their breathe will not offend their surrounding classmates. I don't mind if the kids don't sit in rows. I let them pull up a chair wherever they are comfortable. If that means I have 8 kids sitting across the front so be it. If the aisles are a fire hazard we just won't call the fire department.
I did try a horse shoe arrangement once. I happened to be sharing a room with a new English teacher and since she was new, decided to go along with the principal and use the horse shoe. I didn't want to make it hard for her by rearranging chairs. My class that period was pretty small and well behaved so I figured, what could be bad? I learned the answer to this question very quickly. First, students that usually did not talk in class, became quite talkative. Second, and even more important, the students were way to far from the blackboard and had a hard time seeing what was on the board. While the middle of the room is great for lecturing, and I will be the first to admit that I do enjoy lecturing and putting on a show, it is too hard to keep moving from the middle to the board, which is so important in math.
I'm not against the horse shoe if it works. And it does work in many classes, just not in all. If a teacher is teaching for over 20 years and has been successful, why change? If it's not broken, don't fix it! That is the way I feel about the seating arrangements in my classroom.