Over the years I was saddened to see quite a few old people around whose grown up children rarely visited even though they lived fairly close, I can now see why.
DM has never been a nice person even to the point of DH (and me) refusing to have her in our house (not that she wanted to come as it was too dirty, disorganised and noisy and generally not good enough) but once she retired we all eased up a bit and she visited each week but she has returned to form and gets nasty and abusive about all sorts of things and makes false accusations but if you argue back turns on the tears. The following day she will call asking for help as if nothing had happened. It is not dementia just her true character shining through (backed up by her older sister) but without any inhibitions.
The big problem is that her acquaintances think she is a dear sweet old lady who is being neglected. I imagine this is happening all over the country with many families refusing to have anything to do with their parents or just moving as far away as possible.