That's strange indeed. I've read in several travel books and was told from locals. And when we passed monc kids at the side of a river whith a boat and some people made photos they started throwing stones towards the boat. I took that experience as a proof what I've been told. Hm, but your contrary experience puzzels me. Now I am confused.
Great composition. The position of the people with the leaves and then the building in the background is just perfect - enough context without it being distracting. What are the sticks for - do they mean anything?