Exactly. Theres no such thing as "dating down". The whole premise is based off the fact that they cant get the men they want to date them. So they are dating the men that they can get. They just saw themselves as being better than they actually were. The market will always show the value.
This applies to everyone. Men and women. The entire Coli posts "dimes", but according to the law of averages, most people, regardless of gender, are 5's. So everyone is pining for 8's, 9's, and 10's while calling 6's and 7's "mid" even though they themselves are just a 5. It's all ridiculous, and it's a tale as old as time.
However, I actually think you can date down. Not in terms of looks or money, but in terms of self-esteem. No matter how high someone rates externally. If they feel like they are a 5 and have no self-worth, then they become a mark for users and people who want to feel superior in a relationship. This applies to friendships, too. If you don't value yourself and underestimate your worth, then all of your relationships end up being unequal because you've given up your power before the relationship even really starts by assuming the role of the inferior.