(usually these womwn have the worst taste in men)
There's a reason for this and if you've never been on benefits you won't know.
If you can meet your own housing costs and bills without relying on the state then you have the luxury of forming relationships gradually. You can take your time building trust, you can sleep together as many or few nights as you please, and nobody counts, and you can keep both properties so you have your own home to go back to if it all goes horribly wrong. You can move in together, part or full time, and keep some or all of your finances separate, for a while or permanently. You can take 6 months or 20 years to fully share everything. You can go at the pace of your mutual trust and it's no-one else's business.
Women on benefits are not afforded any of those luxuries. You are either single or in a couple and there is no inbetween. If you are in a couple then you must share your home and all of your finances straight away. If you are single then you must share nothing. Any relationship grey area that normal people enjoy will get you investigated and may result in loss of income, including your rent, and so your home.
Women on benefits are normal women and so have the same relationship aspirations as everyone else but they are in a much more risky and precarious position because the benefit system forces them at an early stage into an all or nothing situation with any potential partner.
It's not that 'these womwn have the worst taste in men', it's just that they get stuck with them, having been required to share everything at far too early a stage in their relationship.
This is a huge part of why women on low incomes are vulnerable.
WPH do not solve this problem directly. Lots of their tenants will still be subject to these BS benefit rules, but by giving women an assured tenancy they provide good additional security. As long as she can meet her rent somehow, and she does not breach her tenancy (e.g. serious antisocial behaviour), then a woman has a secure home for as long as she needs it.
No joint tenancies means that any man who moves in will not have housing rights in her home unless she marries him. She's in a much better position than a woman with a private AST who has at most 6 months security in her home and at least 2 months before being evicted for no reason. If she's a lodger or sofa surfing or whatever she has even fewer rights.