its not just an issue of sorting out differences, but not letting issues develop in the first place. it appears that ppl let too many small things get to them. it becomes an ego issue.
if it is an orthodox, stuck in 1800s type of joint family, where the bahu is not expected to talk, then yes, she relies on her husband for support and comfort and he has to try and make sure that his family's lack of progress does not impact the emotional and mental health of his wife, This does not mean though that the wife abandons her responsibility to learn how to deal with people, and to pick which battles to fight.
sadly, I have seen and heard about the same arguments take place among educated ladies, girls who have professional lives and deal with clients, associated, students, govts etc, but when it comes to home life, all the skills abilities that work in professional life go out the window.
aside from the suppression you talk about in orthodox old fashioned families towards bahus, in many cases such sort of families usually marry within similar families and those girls ae never equipped to deal with others, the level of maturity, ability to deal with conflict etc is low to begin with. and I can see in those cases an uneducated immature saas, an immature bahu..thats a recipe of conflict right there