I don't understand either. Some women lurch from one disastrous relationship to the next, not pausing for breath, having babies with one or more of these useless 'men'. Some are scared of living alone while I preferred it a thousand times over dealing with one of these losers.
I had a standard when it came to men which I learned from my DF. He was hard working, generous, kind, gentle, funny, did his share of house cleaning and childcare even though he worked six days a week and that was in the 1950s. You won't be surprised to learn that the men I went out with rarely met those standards so I quickly learned to lower them but would immediately dump those who didn't even begin to come close.
I get depressed reading on here, virtually every day, threads by women who are not married, live with their DP, have no financial investment in the home, have child/ren, become SAHP and suddenly DB starts to treat her badly, she hangs on for grim death despite emotional/ physical abuse. He by now has found someone else, woman and child/ren thrown out of home with no money. Rinse and repeat.
I don't know how you begin to help these women and I don't mean financially or materially - they need to learn what acceptable behaviour is by a partner and that living alone doesn't mean the end of their lives.