Two non-egalitarian reasons might be: * The kind of teams that are hostile to female programmers are usually hostile about lots of other things too, and hence

Two non-egalitarian reasons might be: * The kind of teams that are hostile to female programmers are usually hostile about lots of other things too, and hence are less pleasant places to work. * Female programmers tend to be better communicators than male programmers. While all the “true wizards” I have known have been male, you need wizardry about 1% of the time, but you need to communicate about 100% of the time.