One thing that strikes me in the swirling debate about the lack of female columnists is that so many people are deliberately pretending to misunderstand what the issues are - specifically whining that there shouldn't be "affirmative action" or "quotas" or whatever and that even raising the issue (cough anne applebaum cough) somehow discredits the women who have been given slots in leading papers.
First, if there's any field which is clearly the antithesis of meritocracy it's punditry. I don't mean that simply as a slam against the numerous hacks who practice it, it's simply a recognition that decisions about such things as awarding columnist slots are based on numerous reasons which have little to do with "how good" of a pundit someone is.
Second, the reason to make an extra effort to add women isn't about practicing the sort of affirmative action which leads to women who are less deserving than men to get the slots (as if there were a "g" score for pundits or something) -- it's about recognizing that for various reasons absent conscious and consistent effort "good women" are more likely to be overlooked.
And, finally, absent her turning them down the fact that Dahlia Lithwick doesn't have a regular column at a top daily is proof that "good women" do, for some reason, get overlooked. Anyone who can elevate Supreme Court reporting to the level of quality literature should've been snatched up long ago...