What this argument assumes is that there will always be a way for couples to access the services that one service-provider denies them. This may not be true.
One problem is that it is difficult to define at what point the couple would be denied of the service. How do we tell what a reasonable alternative is - is 50km further okay? What about 100km? If everybody in your town refuses to serve you, how far out would it be considered an acceptable distance for you to go?