Edit: I've been ignoring this premise for the sake of argument, but now it's time to raise an objection: Men aren't harder on other men. Both men and women are harder on women. This article itself demonstrates this. (It's more complex than just "being harder on." But, in the context of this article I take "being harder/easier on" to be short for "tending to respond negatively/positively to verbal contributions, regardless of the contribution's merit.")