1. The point of the kick is not to kick it as hard as you can, but to get it in the goal so many participants do not focus on kicking it hard because they are focusing on accuracy. A rolling shot that dribbles in works fine.
2. The participants are nearly always wearing street shoes (or even sandals or barefoot) so they cannot get the footing needed. If you give those people cleats and that young lady loafers, you would switch the dynamic.