"I tend to agree. What harm do these folks do by choosing not to have kids?"
A good question. Perhaps the harm is in creating envy among those who do have kids. I know there are a few couples I know who resent my wife and I for not having them. We can do as we please and never need baby sitters. We don't have to plan for college educations and can travel as much as we like, within the confines of our careers.
We pay property taxes (and big ones) to support the public schools, so in a way we're subsidizing those families who have children.
It's a silly discussion.
Besides slapping God in the face (artificial contraception is like binging and purging, except this is "binging and purging" with the greatest human power, the ability to co-create children with God), the implications for society are obvious.
That's an astute observation. Sadly, it really does seem to come down to that, for some of the married-with-children folks. Kind of ironic...