>What's significant though is the PREVALENT opinion. 100% of my religious friends want and have kids, while the majority of my secular friends do not.
Do all of your religious friends subscribe to the same religion?
If so, does this religion proscribe having children and raising families as a necessary, or desired, component of the faith or community?
Because you could be confusing religion and culture here. Secular values often abrogate traditional gender and sexual norms, so secular people may not feel compelled to "be fruitful and multiply." I wouldn't ascribe that to lack of religion per se so much as not being affected by the same cultural pressures. After all, plenty of theists are essentially forced into marriage and children because it's what's expected, not because it's what they want.