1) Contrary to popular belief, most prenups are not thrown out -- the only requirements for a valid prenup to survive legal challenge is that both the (future) husband and wife were separately represented by counsel, AND that both spouses disclosed ALL properties (real and personal) they possessed. The validity of a prenuptial agreement is measured at the time it was signed, unless extraordinary circumstances justify re-evaluating it at the time of divorce -- and in such cases, the re-evaluation takes into account the relative importance of holdings. For example -- a normal person selling a startup for millions is an extraordinary event. Warren Buffet selling a company for millions is not. EDIT: Note that I am simplifying the requirements; the others involve a lawyer, so the lawyer will let you know what they are if you ever do a prenup.
2) Spousal support -- does not include money for the children. It is solely to "equalize" income between the former spouses, and can be readjusted on petition at any time by either spouse.
3) Child support -- the custodial parent may not use child support for their own benefit (unless that benefit is incidental to the benefit to the child). If the custodial parent does use child support for their own benefit, the non-custodial parent is entitled to reimbursement for that amount, and possibly a reduction in child support.
Interlude: Nas. Nas is a millionaire. He had a kid, with a woman, and lived a lavish lifestyle. B/c of that, on divorce, his wife and kid get to continue living a lavish lifestyle via alimony (wife's standard of living during marriage) and child support (child's standard of living during marriage). Lesson to learn: If you're rich, live a normal lifestyle and you won't pay (relatively) much in support.
4) Poor people -- whether black or white -- do not trust the legal system. The reasons are mostly obvious. However, a good portion of it is that poor people base their understanding of the law on shows like Judge Judy and Jerry Springer, not realizing that these shows are staged and/or not real courts.
5) The divorce rate for first-time marriages is less than 30%. (20% is the figure I hear most often). The divorce rate for people who have been married before increases by about 10-20% for each subsequent marriage. If you take out the multiples, divorce is actually fairly uncommon. Note too, that the divorce rate amongst college-educated couples (both spouses) is less than half of the divorce rate amongst couples where neither spouse went to college (stats for first-time marriages).
5) Harsh divorce laws discourage divorce. Think about it -- the easier and less painful it is too divorce, the more likely people are to go through with it. Divorce rates jumped when no-fault divorce laws were passed.