Ghettoism has happened in many instances due to the changes in housing policies since the 80s. As governments have legislated more and more for allocations based on need and vulnerability, so we have seen the majority of properties going to people who fit the profile. This means concentrations of families with chaotic lifestyles and high levels of unemployment, along with people who have physical and mental health issues, and elderly people who often feel trapped in what was once an area they felt safe in. Most of us wouldn't choose to live in those conditions, but for some getting a council house is their preferred option.
Mixed tenure estates have been growing, but the recent recession has meant a reduction in building any new homes. I'm a retired housing worker, and have also had experience of living in most types of housing during my life. I'm in a fortunate position now having no mortgage, but thats partly due to my husband and I downsizing to reduce our outgoings in retirement - as many tenants used to do when they were responsible for their own rents. My in-laws, who lived in council accommodation did exactly that.
The discussion about single elderly people living in family sized houses isn't straightforward. There are those whose families live away and they need room for when they visit. But there are also some who can no longer manage to look after their home or garden, often those people have no close family. Home helps and care assistants can only do so much. There needs to be the right support for elderly people in that position, and the right choice of alternative and manageable housing. Some local authorities offer financial incentives to move, along with practical help and the right move can be in the individual's best interests. If they move to sheltered accommodation, it will cost more in benefits, but it will also free up much needed social housing for families.