It's an extreme hypothetical, of course. I would think that any man would want to know, definitively, whether he *IS* or *ISN'T* the father of a child born to a woman with whom he's had intercourse.
The other thing I think is: If a woman is trying to determine paternity, and two or more men are possible candidates...a man who was determined to be the biological father via paternity test should have to financially reimburse any other man who was implicated who'd tested negative for paternity of that child.