I think you are getting people's opinions, it's just that in my opinion there is nothing to be gained by this level of involvement. There are things in your story that would bother me personally in the spouse of my sibling, but again nothing would be gained by saying what those things are. In my experience it is easy to judge the relationships of others but the thing is - people make their choices. This man, with all his flaws, is the man your sister chose to be with and to remain with.
It seems that your sister is involving your mother and your mother, in turn, is involving you. Your mother's outmoded views on gender roles are her own problem, but in general it is wrong for her to be passing on so much private information about your sister's life. I think if you want to support your sister you would be best to refuse to discuss this with your mother. Hang up if necessary. Your mother may complain but in the end your sister's needs should be coming first here and I'm sure she doesn't need a Greek Chorus commenting on every aspect of her life.