Demands move us farther apart
When I make a request of somebody else without including my feelings and needs, it can easily come across as a demand. When I include my feelings and needs before making a request, it helps the other person understand me.
A demand of somebody else to do something moves us farther apart from each other rather than closer together. It implies blame for not having already done something. It implies punishment if they fail to comply again. It forces the other person to make a choice: submit or rebel.
Instead of a demand, I want to express myself in terms of my feelings and needs, and ask the other person if they're willing to do their part.