There seems to be this common misconception that child-support money received needs to somehow be dedicated to purchasing good that are visibly and directly beneficial to the child(ren) in question. I have often heard people say things like "Why should I give my ex-spouse $2,000 in child support? Clothes and shoes and food for two kids doesn't cost $2,000 a month!" What this attitude doesn't take into consideration is that child support payments are just that: funds to support the children in the lifestyle they would have if both parents (and their incomes) had remained united.
Child support absolutely should be spent on clothes, food, and daycare costs. But that is not ALL it should be earmarked for. Child support is mortgage/rent and utility money, as well as money to maintain the household through the purchase of any items to clean, maintain, and make life more comfortable. Child support pays the plumber to come in and fix the toilet everyone uses, and pays for the new couch in the living room that everyone sits on. It pays for haircuts, shampoo, deodorant, laundry detergent, make-up, pantyhose, clothes, and anything else the children need to be presentable and the primary care-giver needs to be able to go out to work everyday to earn money for his/her family. It even pays for dinner or a movie or a good book or a night out without the children for the custodial parent to recharge their batteries and remain sane while raising children without the full-time help of their other parent. A person who does not pay their court ordered support because the money 'benefits' an ex-spouse they harbor resentment for is a ridiculous excuse for a parent.
There are, of course, situations in which the custodial parent is untrustworthy with the funds and a poor caregiver to the children. I do not deny these situations exist, and I can imagine how hard that must be for the non-custodial parent. If the children are receiving adequate support and are still lacking basic necessities, there are legal avenues that can be pursued to have support orders decreased/increased and custody can be challenged by the concerned ex-spouse. In my experience, however, the vast majority of custodial parents do NOT make poor financial decisions. There are hundreds of thousands of single parents in the world today that exist with NO child support from the other parent of their children. They shoulder the burden, alone, of parents unwilling to contribute to their children's financial well-being because they can't get beyond their resentment.
I have two step-children, and two biological children. They are all my kids. When I fell in love with my husband, I knew that I'd have to love his kids as well, and each month he writes a hefty child-support check to his ex-wife. Does it grate on me sometimes? Yes. Do I agree with all of the financial decisions she makes? No. But I know that my husband and I would never begrudge the children anything. The bottom line is that when you make children, you make promises. You promise to give them a loving and safe life with all the advantages you can comfortably provide. And if life leads to a place where your children require financial support as a result of their parents decisions to dissolve the family unit, it is your responsibility to pay it.