My husband pointed out these stats from Mint.com regarding social change:
50% of people 65 and over believe "The main purpose of marriage is mutual happiness and fulfillment rather than child-raising." However, only 70% of Baby Boomers and Millenials agree.
66% of Baby Boomers agree that "Divorce is preferable to staying in an unhappy marriage," however, only 54% of Millenials and Generation Xers agree.
To me, it sounds like people get married for personal satisfaction, rather than to have children; whereas, younger people are more likely to tough out a more difficult marriage (I'd assume at least if there are children in the family, anyway). Maybe the younger people had parents who divorced and learned that's not something they want to do.