It's viewed that sexual and emotional dependency is normal. You want people who are forming family groups to need each other emotionally. Or if you don't want i

It's viewed that sexual and emotional dependency is normal. You want people who are forming family groups to need each other emotionally. Or if you don't want it, then you at least accept it's the natural 'cost' of coupling up and expecting people to raise children together. Financial and physical security can be outsourced, and the wealthier people have always outsourced that to someone outside of their partners. For example, one could expect the Queen of England didn't really need her husband to protect her, nor give her money. However, she might still naturally like to live with the man more than other people (emotional dependency), and have children with him (sexual dependency). If you remove sexual/emotional aspects of a relationship then all you're left with is the transactional, and that seems inhumane.