Just little things like what that statement was based on. Things like employment, training, experience...
Sociological research done on prostitution as well as personal anecdotal evidence.
I work in an industry where it is very common for a boss or a client to hire the services of strippers and prostitutes.
While I work at a firm now where these practices are thankfully barred and well-policed, that wasn't always the case.
My practice was to either decline these women's services outright or - if impossible for political reasons - to engage them in conversation in lieu of the usual activity.
Pretty much every conversation revealed a skilless woman who had started stripping to support an out-of-wedlock child, or had been encouraged into the lifestyle by friends (who were remunerated for recruitment) or a leeching boyfriend or a drug habit (this last was almost never admitted to openly).
Inevitably, stripping morphed into turning tricks - i.e. either you help out this customer or I'll ban you from my club and make sure you can't get work elsewhere (implicit or explicit threats).
Pretty much every one of these women came from a seriously dysfunctional home, and I suspect many were sexually abused by maternal boyfriends. And these were the ones who spoke English well.
Not once did I encounter a woman who told me: "You know, I was going to take an entry-level job at a design firm, but I thought about it for a while and decided that prostitution was the thing for me instead."
I saw a parade of women with broken family backgrounds, no other marketable skills, no education , etc. trying to put a brave face on a horrible situation.
I did not see any happy entrepreneurs.