The leisure time thing makes perfect sense. If a man works 40 hours a week, the woman does not work, and by 'work' I do include being a carer -which is very much real work, then of course she should do all the bloody housework. Seriously, it won't even take her 40 hours-unless she is super fussy!! So she will still be left with plenty of spare time.
To be honest, in this situation, it is the men who are taken the pee out of.
But when the couple BOTH work full time, then it is a different matter. And women are getting pissed off with going out to work all day and having to do the chores every night as well. You come in, want to watch a bit of telly and have a glass of wine, but, no, you can't because you've got to put a load in the machine, cook, and do the washing up/load dishwasher.
Resentment builds quite fast, and, frankly, women get pissed off. They have the financial resources to leave and feel confident in their ability to cope, so they get out. The excitement has gone and all that is in place is drudgery.
It's obvious to me that the divorce rate is going to rise in tandem with women's financial independence unless men do their share around the home.
I don't see that it makes any difference if couple are cohabiting/married, though, society still expects people to fulfill the same roles whatever their legal status. Such things only matter if you split up/die.
I think to believe that cohabitation is somehow more equitable and fair is to be mistaken. Single means not living with a man, not a legal status.