In general, it depends on where in the world they are, and in general (if we're framing this in terms of the same women for whom a hackathon might be accessible), they are driven by characteristic/ psychological factors (Sexually Transmitted Diseases:Volume 26(2)February 1999).
That's also pretty demeaning to women whose choices deserve to be respected, rather than pitied ("poor, silly women!").
Desperately trying to escape the shittiness of your life through drug abuse, and from there getting into prostitution, is still desperation.
Say what you will about respect, but I find it disgusting that our society demeans women by congratulating them for entering sex work as a profession. ("Oh good for you, you made a free choice to take off your panties for me! What a sweet little empowered capitalist you are!") There are plenty of abolitionist women's groups around the world that agree, for example:
Say what you will about personal choice, but I find it empowering that our society enables women by letting them them freely enter sex work as a profession.
^ See what I did there? You believe sex workers are homeless druggies, I believe they are efficient businesswomen. The truth probably lies somewhere in between. At some point, it basically becomes your personal views about exchanging sex for money, and the morality involved therein.
Which is exactly what I'm saying about the current fracas -- it is a few people who have quickly-offended personal moralities that have been outraged by TitShare or whatever. Tying it to a larger issue of "this is why women don't work in tech" is a futile exercise.
There are also plenty of women that will tell you they are freely choosing to submit to male authority by wearing a head scarf, or binding their feet which requires breaking the arches so they can fold them in half (in centuries past), or working for significantly less money, or, or, or...
In general, I don't take people's words about the freedom of the choices they've made at face value unless they've first convinced me that they're actually free to make those choices, and that includes freedom from longstanding emotional baggage and unresolved internal conflicts.
That's also pretty demeaning to women whose choices deserve to be respected, rather than pitied ("poor, silly women!").