ARGH. This is a) unacceptable, and b) so. fucking. preventable. See: SheSource, The Li.st, The OpEd Project, POWER Sources Project, LadyJournos.
Still: this is bigger than a sourcing problem. This is a byline problem, a Style section problem, a language problem, a trend story problem, a lazy journalism problem, an oversimplification problem. Also: I fundamentally reject the notion that women are less likely to want to be quoted.
There are free online databases to check for plagiarism. Maybe what we need is a free online database to check for dumbass, avoidable gender bias.
In an analysis of 352 front-page stories from the January and February of this year, a study found that the New York Times quoted more than three times as many male as female sources. Read more at Poynter