I for one do not wish to offend anyone's doctrinal stances, and I realize this is a volatile topic that keeps resurfacing. You are correct, in that John does obviously allow differing viewpoints and beliefs to be shared here. Since he is the owner, he can do what he wants.
He could kick people off. He could post a list of rules and statement of faith to abide by. I for one can avoid topics reflecting doctrinal beliefs. But if enforced it would probably dry up the possibilities available to write about, and it would in effect quench the Spirit, which we who are led thereof would be left with political correctness and possibly be rendered to bystander status.
No one is attacking anyone, trying to ridicule or trying to push a knowingly heretical belief system.
I have been to sites that the Moderators would pounce on anyone with threats of being banned for straying outside allowed boundaries of topic and belief. I believe so far we have put up with each other out of consideration and understanding that we are a diverse belief group.
I've seen sites reduced to ghost towns because people get tired of preaching to the choir. If this place were reduced to like minds, the body of Christ here would be reduced to a "So and So's only club " IMHO.

Please John and doves don't do this
Bless you all

Alan T