I tend to agree with the coward part. Having been married to a man who hit me and injured me in other ways, I can tell you that part of it is about early childhood training, part of it is about extremely low self esteem on the part of the man, and part of it is about the need for power over someone smaller and weaker.
I have never met a man before or since who was so afraid of so many things. If there was a scary noise outside, I had to be the one to investigate. He had terrible nightmares, and used to wake me up yelling in his sleep.
I do think there was an anger issue also, and possibly a drug use and alcohol issue, and a bipolar issue.
I do not know if these men are monsters, but they are very probably psychopaths. Sociopaths have no conscience, and that is the only difference between them and a psychopath. Who knows what they feel inside? They are very good at hiding it if they feel anything other than anger.