There's another twist to it: a weird guy in their life having ideas and starts pushing them on his lady. A young good looking woman can be doing fine, have an education and making use of it, then falling for a retarded bad boy or otherwise nice perv. If they're really young and leaning towards the trashy side uneducated the guy probably sees it as a get rich quick scheme, if they're on the other side of 25 it could be swinger ideas in addition to money. Mercedes Carrera seems like someone that had a normal life and a job then I think she got a divorce(it's in her thread) at 30 then probably met a guy that turned her life towards porn and now she's in jail awaiting trial for meth and kiddie diddling. Didn't she work for IBM? Either way, it certainly seems like the catalyst was the new dude entering her life, if she had gotten cats instead of him she would probably still be working at the company she was at.
My hunch is that the "why would she..." type of girls didn't act entirely alone. By the way, wasn't Vicky Chase a Florida swinger for a decade or more before going into porn, then her husband killed himself because her being in porn wasn't what he thought it would be?