I read post #13 in reply and wouldn't agree either with the context-less idea. Someone might have children for arguably selfish reasons, and someone might decide not to have children for arguably unselfish reasons.
But I still can see lots of people not having children for arguably selfish reasons, too.
Look at the popularity of the very term "child-free." It gives me the impression, especially in hand with all the other "-free" terms, that children are a nuisance, an inconvenience, a burden--or worse. Even if I had decided not to have children for Personal Reasons, I could never identify myself with that term or with a group using the term--unless I actually agreed with that impression.
I'm not so sure that "childfree" has a positive connotation, any more than "childless" has a negative one.