I always like fishing a spot by making a few casts and take a step down stream, make a few casts, take a step down stream. When I get to the end of the hole, run, riffle or whatever, I move back up. Can't do that when 10 people are trying to fish a 50 yard stretch of water.
I think it's just poor etiquette to move in to where the other guys swing is ending and stand there. I get a lot of hits from fish at the end of my swing, when I start stripping back in a few feet of line before my next cast.