Just because I think that in a world where it is almost expected that women who are who either married or in settled relationships should have children, and that it's the logical next step to absolute fulfillment in life, they are not bowing to the pressure from either society or their families and are just pleasing themselves.
They are not focussed and driven career women either who are relentlessly climbing the ladder and have put family plans on the backburner, they just don't want children.
I don't know why but I just find it rather refreshing.