Here's the idea: everyone needs covering–a kind of spiritual protection against the storms of life. If someone moves out from under covering, (as in leaving a particular church, or more specifically a particular leader), they somehow become vulnerable to demonic attack and are likely to end up with all kinds of problems. House churches are especially vulnerable because they don't have any kind of covering–no one who has spiritual authority over them. Their leaders don't answer to anyone.
The idea of covering is totally non-Scriptural! The only reference to covering of this kind is the story of Ruth and Boaz where Ruth asks Boaz to extend the borders of his garment over her. It's very far-fetched to apply this to church leadership.
As Frank Viola says, I think in Reimagining Church, it is extraordinary that when Paul writes to the people in Corinth addressing a serious moral problem in the church, he does not ask the leadership of the church to deal with it. One would have expected him to ask the elders to handle the situation. Instead, he addresses the whole body and anticipates they will deal with the problem.
Jesus is the authority to whom the church answers!
(For those interested to explore further, I came across this article by Jon Zens looking at the topic of authority by examining exousia, the Greek word for authority)