@Dan yeah that is stupid. Nothing to do with people stacking rocks.
Also… the fuel needed to burn corpses, the carbon released in the process, the manpower, the vehicles to move them, the carbon footprint to make the vessels….they all leave a trace, which is fine, as there is no such thing as leave no trace. We can aim at leave “little” trace, that is it. Personally I would rather be buried up the hill with no casket.