It is a genuine fetish, all about feminine supremacy and control. Yes, quite a lot like being married then!
The problem is, many ladies jumped on the bandwagon after the rinsing programme, looking for easy money. They think they have to call their admirers "wankers" or "faggots" or whatever nastiness comes out naturally to assert their...assertiveness. To me, it just looks childish "hey you wankers, gimme your money so I can buy shoes" *yawns*
I have dabbled in FinDom, but I'm not a nasty person, so came at it from a mothering, nurturing angle (with a bit of discipline thrown in). And I can tell you that it's FAR from being "easy money", the slaves and subs are so demanding, they want your time and your chat and want to know everything about you, and if you don't read their email within 30 nanoseconds of them sending it, they get all whiny and huffy. I'm telling you, it's MUCH easier getting money for opening your legs, sucking cock, or doing light domination, than it is to do Findom PROPERLY. Takes a lot of time and effort on the Dom/me's part to get it just right in order for the payments/gifts to start coming, and then you have to up the time and effort to keep them coming. Easier to get paid for an hour's booking - you get money, have sex, he goes home, everyone's happy.