I'm baffled why the article has (apparently) drawn a lot of fire. It strikes me as being thoughtful and commendable, if just a bit "safe" -- as if written by a committee and carefully polished by a public relations firm. But major criticisms? I don't have any, but do think there's something facile about the reasoning in this one passage--
Ultimately, it is society that must change, coming to value choices to put family ahead of work just as much as those to put work ahead of family. If we really valued those choices, we would value the people who make them; if we valued the people who make them, we would do everything possible to hire and retain them; if we did everything possible to allow them to combine work and family equally over time, then the choices would get a lot easier.
It's a lovely thought, but I think Slaughter is overlooking the fact that sometimes putting X ahead of Y means really not having the time and energy to be fully committed to Y. It would be the same with a marathon runner who is constantly training, so only able to work very limited hours. Or someone who chooses novel-writing over lawyering, so rarely shows up in the office. A choice can be praiseworthy without necessarily being compatible with hiring and retention. This is the cruel and tragic truth. I don't think there's always a societal solution ("Ultimately, it is society that must change...") to the sort of quandaries people face when they greatly value both X and Y, and there's no practical way to choose them both. Some of our problems are really our problems, not "society's" (duh).
Maybe it's a noble lie that society must change, that it's always a question of workplaces needing to do more to accommodate choosing family over work. If we go around telling that lie, workplaces will do more, and at least more women will be able to continue to work. I want that to happen because I'm thrilled when I see more women in top positions. But if you're interested in the whole truth and nothing but the truth, I think you have to admit that the parenting urge can sometimes take you so far from full time work that retention is basically impossible.
A more plausible point here would be that choices to focus on family not work don't usually last forever. Employers could do a lot more to welcome back people who have temporarily decided to be full-time parents.