Maybe the motivation has nothing to do with any of the above, maybe it's psychologically motivated, here's my new theory. How many places can you anonymously stick up for someone you like?
What these guys are truly doing, under the pretension of coming to providers "defense" is seeking to protect a personal resource, and perhaps gain special status with that resource.
It is almost the way a junkie would come to the aid of a favorite pusher. "I got to protect my source, Man!"
I'm not saying 100% of the time. Just often enough that you really have to question it when you see it.