I was married in the 70's like many here. Yes, we were expected to put up with the bad bits ."You've made your bed, you should lie in it" was common advice by parents to their daughters and sons.
When I look back I can honestly say that I should have left my 1st husband in the first year - his behaviours were appalling and I felt trapped. I used to plot to leave and go "back home" but my parents would have simply told me to go back to my husband . With no alternatives, I stuck it out for another two decades before I was able to leave and make a new life.
I don't blame the young ones for having no patience for the "irritating bits in marriage" . I doubt that they leave for no good reason , but they are rightly unwilling to put up with the awful behaviours which we, their mothers, tolerated because of social pressure and parental disapproval. Good for them.