Organized crime probably was the supplier of women and drugs - isn’t there a big human trafficking trade in Europe?
The pot was legal, so I doubt there was enough profit margin there to interest OC types.
However, darn few women have a true yearning for prostitution as a career choice, so they must be “encouraged” to pursue the career path, whether by addiction to other still illegal drugs, physical abuse or human trafficking.
OC can make lots of money in all these areas.
Plus, if you want to score some illegal drugs, a logical place to look is around where “legal” ones are being sold.