Here are my 2 cents on this one:
1) It’s very easy to condemn him because he ‘didn’t listen to da’as torah’. Whatever he was told, might not be easy for him. He may not have the skills to get a job. He may not know how to or be able to get a job that he feels is mechubadik for him. Granted, he needs to swallow his pride and do what he needs to do to provide for his family, but that may be very very difficult for him to do.
2) Not having a job for a guy is like not being able to have children for a woman (give or take- this is not a scientific observation, just a sense that I have)- it does serious damage to their self-esteem, identity and sense of self. He is probably feeling really bad about himself and about the fact that he is basically living off his wife.
3) I would say he needs some help (therapy) possibly with his wife, but definitely also by himself. If he wont go, then I would suggest the wife go on her own to see what she can do to help him. He sounds depressed and suffering from low-self esteem- both can be (somewhat) helped in therapy.
4) For starters the wife can (I know this may sound counter-intuitive, but if she wants a positive outcome and not just start the slide down towards divorce) be positive and encouraging to him. Appreciate every tiny thing he does, help him feel good about himself. Ask him for advice on her business, the kids etc. Let him be the man whenever she can. I’m sure she has done/tried these things and it may be really difficult, especially when the tension (and resentment) has grown over the years.
I’d say, bottom line, if she were my friend, I would encourage her, remind her why she married him, and how much she loves him and try and encourage her to go to therapy so that they can salvage their relationship and do what she can to get him to go as well.
Good luck and on behalf of the Klal- thanks for trying to help your friend and possibly avoid the breakdown of another home in klal yisroel.