It's never good to simply generalise, but most of the WG's i know on a personal level have very destructive, complex issues to deal with.
Negative early life experiences, few, if any 'real' friends (friends are usually BFFs after a week, then are gone just as quickly. This suggests some sort of attachment disorder).
They have experienced no structure in their early lives and poor role modelling, so have little if anything on which to base how 'real life' works and what is acceptable socially.
Drugs/alcohol and self-loathing/self-harm are just some of the ways in which they attempt to mask their day to day misery.
No surprise then that they cannot hold down a 9-5 job; even being sacked from McDonalds ffs.
The need to supplement their benefits (cos lets be honest, most still claim them) means selling their only asset, their body, is the only way they can fund their needs/lifestyle.
I agree with this (a lot of punters on here seem to have a very "rose tinted" view of WG's and their earnings) I've known a few working girls over the years (outside of the bedroom) nearly everyone has had some underlying issue (not always obvious initially) it often explains how they've got into the job, or some issues can be caused by or made worse by the job (drink drugs etc)
For many of them leading a double life isn't easy, there immediate family or partner might know what they do, but wider circle of friends don't, this is often why they don't have many friends (especially girlfriends as they can be very "bitchy" apparently
) and as you say why friendships come and go suddenly, I mentioned on another thread about talking a WG out of taking her own life, she later said she could never thank me enough and we would be friends "forever" that was until she got a normal job and I never heard from her again
The ones who are a bit more "normal" can still find it hard living the double life some have normal jobs and just work part time, which can be a good cover, but these days having and using large amounts of cash isn't always easy (especially for any that are claiming benefits) and is often why money is "wasted" on silly things
Edit
Something which they do get very good at is lying, it becomes second nature and almost the "norm" for some, often t all comes out eventually though