I'm going out on a shaky limb here, but it's my opinion so...
perhaps it's because more 'consumers', unable to find willing indulgent playmates for free (they do exist, BTW) find the 'trap/interrogation/kidnapping thing' to be a more realistic way of satisfying the fantasy, at least in their own minds.
The concept of a willing happy girl is beyond them.
Gentlemen, at the risk of repeating myself, They Do Exist. Lots of them.
And for those of you who prefer the concept of an unwilling 'encounter', hire a sub at the Dominion or suchlike, explain your requirements, and fantasize/make-believe away.
It might not be absolutely real, but at least you won't have any worries about going to prison/disposing of the body...