I don't think it's loneliness. It's like the trope of the rich guy that is addicted to hookers. I think for a lot of these men it's just an addiction, and for many others it's probably the cause and not the result of their loneliness. I'm sure there are some that are in a pit of dispair and loneliness just grasping at anything, but those people can't be helped, they can only help themselves, but they won't.