Magic Man
Reaper of Conversation
I wouldn't have such a problem with this if it weren't so one sided. Even though there are just as many women who behave badly, but it seems when women behave badly, society is less likely to vilify her (compared to bad men) and more likely to make excuses for her behavior. I remember when Obama was President, he gave a speech during fathers day. He spent most of the speech talking about how he didn't have a father around when he grew up and encouraging men to "step up" and raise your kids. Can you imagine a politician giving a mothers day speech focusing on bad women and telling mothers to step up?
There's just one teeny tiny problem with your grand theory here: the problem IS one-sided. Women don't behave badly toward men the same way or at the same rate as men do to women. It's a problem with men specifically, not people in general. (Note just for you: this doesn't mean women don't behave perfectly, just that it's not nearly the same as men.)
Why would anyone tell mothers to step up? They're still expected to be the ones to step up all the time. Fathers are still not given the same expectations as mothers, because there's still the old mindset of "that's women's work/the mother's job". There's still the pervasive idea that guys taking care of their kids are "babysitting". Because of how widespread male bad behavior is, women still have to do most of the taking care of kids.