If "The basic foundation of marriage (historically) is a financial alliance and this hasn't changed much" then it's no wonder why there are so many divorces.

If I want a financial alliance, I call my banker. If I want a relationship where the happiness and well being of the other person is the foremost goal, if I find trying to do this makes my own life all the sweeter, and if I find that person feels the same, then I've got at least the first row of bricks in the foundation for marriage.