Why would anyone go looking for substantive debate by making a statement and letting anyone on earth reply? You wouldn't let most of these people into your hom

Why would anyone go looking for substantive debate by making a statement and letting anyone on earth reply? You wouldn't let most of these people into your home; why would you expect an arbitrary one of them to be a good conversation partner on an important controversial topic. Reputation matters. Filtering matters. Selectivity matters.