I don't want children...but I never call myself childfree.
I will freely tell people I don't want kids if the topic comes up, but I will never in a million years say the words "I am childfree." In my brutally honest opinion, it is because the majority of the childfree people I've come across are complete losers. They all like geeky crap like fantasy/sci-fi and anime and go to those geek conventions like comic con, plus 99.999999% of them own multiple cats (ironic because they hate being stereotyped as child-haters or sexual rejects, yet they own a crap-ton of cats which is one of the most common stereotypes of people without kids). I have yet to come across a CF person that would much rather watch a marathon of every single episode of all the Real Housewives shows than nerdy bullcrap like Pokemon or whatever. Plus, if your "lucky" enough to see pictures of them you'll see that a lot of them look like your typical basement-dwelling social rejects. As much as some people don't like to admit it, this is a pretty shallow world and I think it's in my best interests that if I want to get ahead in life I should not associate with people that look like dweebs because if I do people think I'm a dweeb that can only get work as an overnight cashier at a Walmart that's open 24 hours (they don't say "you are the company you keep" for nothing, you know). So that is why I don't call kids but I don't call myself childfree.