Putting up a dysfunctional group wall ...or a ''blue'' wall, or a ''white''' wall, ensures the protection, support and enablement of whatever abuser, ass-hole, or monster is inside ''those four walls'' with you. Evil grows in the dark- like fungus. Often the real 'threat' is coming from inside and not from outside.
This ''closing of ranks'' to protect a group, based on being a part of the group, rather than on discernment, principles, ethics or evidence has to go, as this is the nature of dysfunctional relating and part of what keeps it going. We cannot ''fix'' what we are not ''allowed'' to see or hear.