I'll tell you exactly why no rector would encourage fertility in his congregation: those whiny kids might disrupt the service. Having a baby let out a fuss while the choir and organ perform the Gloria in perfect 3 part harmony would eliticit the same indignation as someone spitting on the host in a Catholic Church.
I later mentioned it to a dear friend who is an Anglican priest. He dryly replied, "Ah, children. At St. Margaret's they are vaguely aware of them, not sure where they come from, and are thoroughly disgusted by the whole process."