In addition to IntronExon's points, the very headline of the article points out that these experiences don't happen as often to men. And they generally happen out of the sight of other men.

Thus even the men who are aware of the presence of bad actors are sometimes blind to how many of them there are, just how horrible their actions are, and more importantly who the bad actors are.

And because of this, a) it's harder to grasp the extent and severity of the problem; b) they may not know whose behavior needs to be corrected; and c) they may rationalize or deny a bad actor's misbehavior when someone does point it out because their experiences with him have been positive, so the accusation causes cognitive dissonance.