Sinners?
Let he who is without sin cast the first stone!
I'd much rather commit the "sin" of sterilization than the heinous [censored] that some people do to their own kids...abuse, neglect, beatings, murder even. I think compared to all that, God can forgive someone for wanting to be childfree.
(Note also I said *some* people, not all...I don't want to get flamed by anyone here...)