50 shades is just the first time it went super mainstream. "Romance" books have been around for generations, as has fanfiction, and nearly everytime its the same type of man and sex.

But I don't see it as their desire to be a gold digging leech. I see it as them wanting to be completely without responsibility or power under a dark man who abuses them "with love". Its mass appeal just says how un-diverse they are in their sexual desires, because women are average as biology proved long ago.

Which becomes a problem when they cannot separate their horny from reality, so they seek those men out (who rarely are as benevolent as they are in fiction) and then cannot accept responsibility for that mistake (because they are women) so they take it out on everyone else, including their newborn babies from that failed man.