A scene is not just a bunch of people interested in a thing. It’s a bunch of people interested in doing something new with a thing. Because Scenes are people producing work aimed at impressing and one-upping each other the people in them by definition need to be doing something new (at least locally.) How else can you one-up the other people. A scene can become world class when it goes from doing things that are locally new to things that are globally new.
Since Frontier-dwellers tend to live in developed places it makes it more likely that scenes will happen in developed places and specifically explains the first half of Florences require a world-class high-profit discipline and a world-class cultural discipline.