Thank you for this. As a man in his 40s who's also dated younger women, I can say that many men do want to settle down with them and have a relationship and family. Unfortunately, many women that age don't want the same thing. They want their career and freedom instead.
More and more I see middle age relationships deteriorating as a result of power struggles, resentment, anger, distrust, and a lack of curiosity about the opposite sex. The opinions and feelings have calcified into a set of beliefs and an unwillingness to adapt to another person.
In otherwords, I think the biggest hindrance to middle age dating is rigidity and a battle for control over the relationship.