Many of the bishops, who are opposed to broadening the field of who can be ordained, come from Africa where the Anglican church is thriving. And where did this belief system come from... It is likely that it came from those who brought it as missionaries carrying The Book of Common Prayer.
"Almighty Father, whose blessed son before his passion prayed for his disciples that they might be one, as you and he are one: Grant that your church, being bound together in love and obedience to you, may be united in one body by one spirit, that the world may believe in him whom you have sent, your son Jesus Christ our Lord, who lives and reigns with you, in the unity of the Holy Spirit, one God, now and forever. Amen" The Book of Common Prayer