Sure. But is it really worse for society to have single mothers on welfare than to have mothers trapped in toxic marriages for financial reasons?
Surely this is an empirical question and not a theoretical one. Unfortunately it's hard to measure fairly. Let me offer a clearly flawed first pass.
If you take, just as a reference point, pre 1960 US society and post 1980 US society as exemplars of "lots of toxic marriage" and "lots of welfare mothers", then I think one would be hard pressed to show empirical evidence that the latter is doing any better than the former. Certainly by conventional measures of success, one could argue that the latter is worse (though there are so many confounding variables that I personally don't feel comfortable having an opinion).
My point here is that I don't think we can presume the welfare-single-mother outcome to be, a priori, obviously better than the old toxic-marriage status quo, when measured by society-level outcomes. There is ample evidence that both cases are clearly inferior to stable, non-toxic, two-parent households. So the question is an empirical one of the lesser of two evils, and I don't think we have a clean way to answer it so far.
This one I don't understand how anybody could ever think a good idea.
> If you punish men in divorces,...a massive increase in male suicide
That's external locus ("avoid"). What should be a real concern for ladies that it would greatly dry up their pool of potential mates.
If you give courts / child protection services a cut of the child support money, you get more divorces where the fathers are cut out of the children's lives.
If you punish men in divorces, financially ruin them ("imputed income"), and don't let them see their kids, you get a massive increase in male suicide after a divorce.