Are there that many? Are you confusing an expression of marital strife with misogyny? They aren't really the same thing, because divorcees usually remarry.
From where I stand: There are a few in the British Traditions, not many. That's TRADITIONAL tradition. And very few racial ones, excepting songs about current enemies, which I wouldn't count as racial.
What do YOU call trad? I'm not going there.
Folk songs were often collected in pubs, or from guys the collectors knew had sung them in pubs, which were once a male domain, so what do you think those guys sang about? Bluebirds? Flowers?

A better question might be: Why are sickly-sweet love songs so prevalent in Pop music? So that they sell to the ladies, possibly? Folksingers aren't (weren't) trying to sell their music.