I don't necessarily disagree with your overall message. But I do think you're undercounting the number of folks who get injured through ignorance. And I don't even necessarily mean traumatic injury. Even just enough injury or soreness to discourage them from trying things again can be problematic enough. Is kicking your ceiling really a good measure of some sort of fitness? Is it worth the risk of slipping and cracking your head? I don't know. Maybe. But it's far more risk of injury than walking around the block a few times and the vast majority of people really just need to start there.

No, you can easily cause injuries from bad form that you wouldn't have gotten simply by doing nothing. I know several people know who broke or damaged something in their bodies and a few who needed surgery to fix it due to bad form over time.