[karpierz]

You're applying your biases to the data.

All the data says is that women think that the average man on OkCupid in 2009 is less attractive than the average man.

Your conclusion: women don't rate mens' attractiveness accurately.

Another conclusion: the average man on a dating site is less attractive than the average man.

Another conclusion: women and men interpret the survey question differently.

You also make the additional assumption that this is some sort of fundamental problem, but that's a separate issue.