And the law still favors women by a very wide margin when it comes to divorce. I don't exaggerate it.

Indeed. As a man, there is no reason at all to get married - you won't get the kids anyway, but at least you won't be saddled with debt to your wife.

I would be willing to bet that the increase in general acceptability of divorce is the main factor.

'the main' I wouldn't say. As women become increasingly economically independent, they open up the practical ability to get a divorce. Many women used to have to stay even in abusive relationships just because they had no other options. Women who can provide for themselves have the option to leave a relationship when they find it no longer in line with their life goals or desires.

Could it be more acceptable because women on their own, as well as men on their own, are better able to survive these days?

I think frozen meals and washing machines helped the cause of feminism a great deal...