They take out their anger on the LBS because it is safe to do so.
On the other hand....
The LBS can only take so much and should not allow themselves to be abused.
There were times when my Husband really needed someone to listen to him, and even though he spewed, I kept my mouth shut. IF he began to cross the line, I told him to take it down a notch so that I could listen properly.
If he didn't, I would hang up the phone and tell him to call me once he calmed down a bit.
I began to enforce my boundaries, and in all honesty, he really did comply with them most of the time.
There can be no testimony without a test. I am praying to go through this test and come out the other end with a new and better marriage then before.