DNA, CHILD SUPPORT & FATHER'S RIGHTS

I was just reading this article in the New York Times and I came away from it thinking that something is wrong with a system that would force a man to continue to pay child support for a child that is not his. This issue of equitable paternity may be well-intentioned in most cases. But is it fair? Certainly in the Times piece, where the wife had an affair, passed the child off as her husband’s, divorced the husband years later, married the biological father of the child….but the ex-husband is still on the hook for child support?
It is understandable why the law is the law on this issue. Children have to be protected. It is not their fault that adults are so full of it. But boy. It sure has a lot of injustice wired into it, for some unsuspecting guys.