How do you explain too someone who wants kids when you don't want them

It seems like most women I match with on dating sites are looking to start a family when I explain to them my reasons for not wanting kids,the topic leads to an argument starting with "weren't you a kid at one point?" And if your parents didn't want kids you wouldn't be here" whether that's true I can't think of anything to say in response to that. Anybody else experience that?