Bear this in mind, I have two children with my boyfriend and we are not married. We own property together and are in a common law partnership.
Being socially responsible is to follow social patterns and rules. Society naturally objects to those who oppose it's social codes. Why do we get married? Without an in depth analysis of marriage at hand my speculations are thus.
Religion dictates to us that it is morally right to be married to our spouse before we copulate with them.
Why? The paternity of children was hard to determine before the invent of marriage. Therefore woman controlled the lineage of their children when religion didn't control whom they slept with. Take a look at early biblical texts. In the bible, a woman would be stoned to death if raped. Why? Because the male lineage would be questioned. It's a basic way in which to control a civilization, lineage.
As more and more woman are becoming educated and engaging themselves within the workforce. They find less time in to find a suitable mate who wishes to have children within the time frame that permits them to do so. These men wish to be boys forever. Playing video games and staying up late. It's profitable from an economic basis, they spend more money on entertainment. These men are unsuitable as mates because they don't want to be parents. Too bad for the woman.
It doesn't have to be. Surround yourself with other woman who will help you raise your children. Friends, family and find a father (a male who has proven to be a decent father to his children) who will be a donor. Eliminate these men from the gene pool and you'll find that society will produce men that wish to father children.
In short, don't be ashamed of your basic biological wants. The woman who will make it are made to adapt.
Sooooo tired. Hope that was helpful. Power to you.