Non-coercive = embracing others exactly the way they are, and they can change if they want to and they don’t have to. Coercive = trying to control, fix or change others against their will.
Coercion is stressful because it conflicts with most people’s wider ideas about morality, human relationships, and how to run a society, etc. Unless one mentions children or parenting, everyone agrees that consent-based solutions are better that coercion every time. That theory is held on some level by most people. They just suppress it in their parenting.