There are an enormous number of (small) churches that don't function as business entities in the way you describe. Taxing churches would adversely select agains

There are an enormous number of (small) churches that don't function as business entities in the way you describe. Taxing churches would adversely select against these, encouraging all churches to behave more like businesses. It's unlikely to me that that's the outcome that anyone wants. If you think Christianity is broadly good and correct, the trend towards business-like megachurches and celebrity pastors is deeply corrosive to the faith. If you think Christianity is broadly bad and corrupt, the trend towards business-like megachurches and celebrity pastors entrenches and effectively promulgates many of the religious ideas that you abhor.