Single, lonely, desperate, and a tad depressed about it is a rather toxic cocktail. Unfortunately everyone is vulnerable, no matter how intelligent they may be normally, if they are in an emotionally difficult state. Leads to bad decision-making. And then there are always nasty people who will exploit this.
I saw an article on internet about this subject a couple of months ago where people had added their comments. One man said Where can I find one of these women......
I wonder if people really believe that in the right (ie wrong) circumstances, they'd never fall for such things, or if they are just lucky. Either way, it's sad when people get into the positions where they think this is sensible. It never turns out well.