Ah yes, without any intention to offend, if someone deserts an ailing relative or two, the taxpayer has to pick up the tab.
Help and support for say an elderly mother would need an adult relative to help, coordinate, liaise with social services and dare one say it - provide family love for a very vulnerable person at the end of their life. It will add to the social workers load if there is no family available - and the mother wont be cared for so well.
With mental health issues, with no relatives to provide support, even just making sure daily that they are ok (I cared for a relative with severe and enduring mental health issues for 9 years) take them out for a walk, shopping, make sure their home is ok, make sure meds are ok - if this isn't done the person is more likely to end up neglected and cost the rest of us in failed community living.
Why would anyone not care for at least one relative - and provide love, set an example to the younger generation over what is kind, what is moral - and not leave it to the already stretched state to pick things up?