So because government welfare programs have destroyed the social compact in many areas of the country, we need more government?
Marriage without government would be a contract between two individuals, and one of the few proper roles of government is enforcing contracts. If a man fails to shoulder his contractually-defined familial obligations, he can be sued for breach of contract.
Marriage doesn't exist without some form of authority to make it exist. It is not an individual act that exists without some kind of government.
Find me a society that has marriage, and I'll show you a tribe, nation, or belief system.
I am singularly unimpressed by libertarian arguments that end in "so they can just sue". They exist in some fantasy world of perpetual lawyers. They put the weaker party (the wife and children) at a tremendous disadvantage vis a vis the stronger financial resources of the male former breadwinner. In a secular world of mobile wealth and mobile people society has no power, absent the power of the state, to fulfil its very real societal interest in seeing to it that women and children are looked after and that the weaker party (even those who don't have the money to sue) is not simply walked over.
In a libertarian world justice is only for those who can afford the best lawyers. A good society has to be better than that.