This isn't nothing to do with labels. This is about raising up a minority group. Seeing them. Recognising them. Celebrating them...
I agree we could do with less labels and more acceptance of people as people. But by giving people who choose not to have children a term, this very act is accepting them as people!
If we have a term for one type - parents, then it goes without saying weneed to have a term for those who aren't parents. The default is not parenting! Especially in this day and age where the rise of people without children is increasing signififcantly.